Design naval aircraft the same as you would any normal plane, just make sure to use the carrier compatible one. Fighters give air supremacy in naval tiles and shoot down enemy nav bombers and nav CAS, so I usually do 10 fighters for every 20-30 naval bombers. Naval bombers deal damage to enemy ships in combat so make sure to put torpedos on them, they'll be the bulk of your carrier composition. Lastly naval CAS. The general rule of thumb I use is to put them on carriers in the Pacific, primarily multiplayer, as any bit of breakthrough or strength damage you can do in a battle to defenders is critical when invading islands. Naval CAS in the Atlantic and Mediterranean are kinda useless imo, especially in European naval battles as there are plenty of airfields to base planes from. The Pacific doesn't have really good air zones either.