The Walking Dead draws most of its inspiration from George Romero's popular Living Dead series of films, particularly the second and third in the franchise. Dawn of the Dead was the middle act of a three-act play, where humanity was on the verge of complete collapse due to a zombie outbreak. The Walking Dead follows a similar story, with a very similar kind of foe.
If the characters of The Walking Dead ever found themselves trapped in Romero's world, it would look largely similar to the one they just left. However, there are key differences in how these two worlds do things, and what worked for certain characters in The Walking Dead may not work in Dawn's world.
Eugene
Eugene survived largely by lying about his own credentials and worth, but that didn't mean he was a total loss. In fact, he was smart enough to think up ways for the survivors to keep going, and rise above many different challenges. He was even clever enough to make ammo for Negan and his Saviors.
In Dawn of the Dead, Eugene would survive if he managed to join up with a group. His intellect would allow that team to bypass a lot of pitfalls, particularly when it came to securing a foothold from which to fight back against the dead. He may have started out as a coward, but Eugene knows how to get a leg up on life's curveballs.
Merle
Had Merle not crossed the Governor, The Walking Dead's most intelligent villain, he'd probably still be alive. This minor misstep was an anomaly for a guy who usually found a way to survive, by either hook or crook. He'd gone up against Rick and lost his hand as a result, but even that didn't stop him from simply attaching a metal replacement onto the stub.
In Dawn of the Dead, Merle would have undoubtedly been one of the bad guys taking advantage of others for the sake of personal survival. It's doubtful he'd be foolish and reckless enough to join the biker gang that attacks the shopping mall near the end of the film. It's far more likely that he'd hang back and wait for the threats to thin out.
Michonne
To Michonne, the world of Dawn of the Dead would be a relative cakewalk. Only by teaming up with others would she face any real vulnerability. On her own, she's clever and able to figure out ways of surviving that are incredibly unorthodox, yet highly effective.
She's at her best, and worst, in a group. She flourishes as a human being, but she also lets her guard down. She wouldn't be lured to the idea of holding up in a shopping mall all on her own, but that wouldn't be an issue. If she remained on the move, it would simply be a matter of avoiding dangers and seeking out resources.
Daryl
The worlds of The Walking Dead and Dawn of the Dead are pretty much identical. Both depict civilization collapsing, and humanity falling into the depths of paranoia and irresponsibility, whilst zombies lurk about in search of the next meal. To Darryl, this would probably be a walk in the park.
Darryl seems to have no trouble dealing with the undead. It's his run-ins with other humans that test his resolve and put him in greater danger. As a lone wolf survivalist, he could slip about relatively unscathed, unless he was lured to the lifestyle of the biker gang that attacks the mall in the final act of Dawn, which is entirely possible.
Morgan
Morgan is the ultimate survivor, though even he may question why. After all, he had little to live for after his wife and son were both killed by walkers. Rick found him later down the road in one of The Walking Dead's most heartbreaking moments. As a man on his own, he was largely dead inside, at least until he found some way to balance his trauma and feelings of guilt with a sense of purpose.
From a purely survivalist standpoint, Morgan was built to go on. He distrusted and verified everyone he met, which meant it was impossible to fool him. He stayed relatively clear of people, kept a low profile, and knew how to circumvent pockets of zombies. Dawn of the Dead would practically be his backyard.
Carol
No matter how many traumatic events and sad things Carol goes through in The Walking Dead, she always seems to keep going. She's lost her daughter in the worst way imaginable, not to mention countless loved ones that she bonded with, only to watch as they left her in turn. For Carol, happiness wasn't just fleeting - it was impossible to obtain.
Yet, something inside of Carol keeps her forging ahead, despite all lack of reason. She'll do whatever is necessary to hang on, including killing members of her own team who become liabilities. She cares deeply about the group she's in, but she's not afraid to sacrifice herself for the group, either. She's more than capable of tackling the similar zombie apocalypse glimpsed in Dawn of the Dead.
Shane
Shane was built to survive in the Walking Dead world. There was no line he would not cross for the sake of staying among the living, even if it meant offing members of his own crew in order to make that happen. Had it not been for his selfish pursuit of Lori and Carl, he would never have let his guard down long enough for Rick to fatally wound him.
If this element were removed from the equation, Shane would have survived for the long haul. He knew exactly when to make a move, when to pull back, and when to utilize others in his group like chess pieces. In the brutal world that followed, Shane's odd mixture of preparedness and paranoia would have made him a tough nut to crack.
Maggie
Maggie is a quick study, and that's not only allowed her to survive the zombie apocalypse in The Walking Dead but also become a community leader at the same time. In Dawn of the Dead, she'd probably do more of the former and less of the latter, but it would still be a valuable skill, even in a small group.
Her ability to adapt to new challenges would keep her breathing long enough to set up something resembling a stable life structure. From there, she'd have to contend with the roving bands of outlaws that would seek to undo everything she built. Having that shopping complex locked down would help lower that risk.
Negan
Dawn of the Dead was the middle act of Romero's original trilogy, and it took place at a point in time when humanity was just starting to unravel. The last vestiges of law and order were breaking down, and it was time for everyone to run for the hills. Negan found himself in a similar predicament in the show, following one of The Walking Dead's most tragic backstories.
If Negan got control of the shopping mall in Dawn of the Dead, his first order of business would be to secure it in the same manner as he did the Sanctuary. The resources contained within, from guns and ammo to food and clothing, would have allowed him to set his Saviors up on a position of immediate power and tactical strength.
Rick
Chances are, Rick would have had already found himself on the road, picking up survivors along the way. The shopping mall would have been the ultimate respite for him and his survivors, giving them an edge when it came to staying alive. From there, Rick would probably have set about creating a community, to find strength in numbers.
The mall would have stood in place of Alexandria, and it could be used to network with other outposts in the vicinity. With so many resources at their disposal, Rick would have had no trouble growing his community and turning it into a base of operations to survive the zombie infestation. His path would be similar in many ways to his trajectory in The Walking Dead, and he undoubtedly find a home in Romero's zombie universe.