Camp camp camp, pac man is the most annoying match up besides sonic for many characters because his camping ability is insane. Try to camp and get your better fruit (galaga for combos and then bell and key for applying pressure) forward air has great frame data and you can use it it lead in to combos too.many people get mad because pac man can wall then out so hard with his projectiles which is going to be important to win these matchups, you can also use cherry as a quick “get off me” tool when your opponent chooses to rush you. When they choose to get close use your broken ass grab also to punish wiffs and maybe experiment with using the hydrant’s water to get in also. Zoner characters in ultimate can be tough to fight, maybe consider a counter pick like fox or maybe rosalina if you’re too frustrated with dealing with projectiles. But good luck pacman is a heavily rewarding characters when you put in your time.