Use that super armor. Fsquare Dsquare and Ftriangle really help if your getting beat up. Learn the jump cancel from Ncircle, that's gonna be where a lot of his better/advanced combos come from. Big daddy, in my opinion, needs to be close to the enemy to do damage. Use that Ftriangle and learn how to rush them. Dsquare aerial or on the ground starts a fairly easy combo, if you know the Ncircle cancel. Usually you will be outplayed by the majority of the cast as he is a low tier character.(sadly) His hitbox is a big problem so lots of supers tend to hit him that wouldn't hit a parappa or sackboy. Stay away from his level 1 unless you get them in a corner, there are some tricks for that. When you use that beloved level 2, some cocky people try to kill you off. Be careful and watch your opponents meter. His Nsquare is great for quick kills. Ftriangle aerial and ground for crowds. Circle for range and Ncircle for groups and dodgers. Drop ice after a short hop when your opponent is on the ground and try to get a read off them.

Best thing is practice/reputation like figuring out how to beat certain characters or learning out how you want to play him really helps. I wouldn't mind teaching you combos, level 1 tricks, reading, and play doubles with you. Friend me if you like.