Can anyone help me? I can't wavedash very well with Falco and I can't short hop almost at all with Fox. Should I stay with Falco and get down my wavedashing orn switch back to Fox and practice my short hopping?
It really depends on which character you have the most fun/think you'll have the most fun with on the "do i stay or switch back" question.
Personally I think Falco is a pimp, and will forever main him, I only recently (two or three months ago) began wavedashing with him without ever messing up, and I've been playing Falco for about 6 or 7 months to give you some perspective. So I can tell you that eventually if you practice enough you will get the timing down on the wavedash.
So it's really up to you I'd bet that you'll have just as much trouble getting short hop consistency out of fox that you have right now with Falco. Also with time your thumbs will get faster regardless of whether or not you switched mains and after awhile you'll be able to short hop Fox even if he's not your main. If it were me, I'd stick with Falco because he's a pimp but it's up to you.
tl;dr:
Play who ever is fun for you, they're both technically demanding characters either way you'll have to practice ****loads before you can do everything you want.
Edit: It may also help to note that Falcos awkward wavedash is due to the fact that when you press jump he bends his knee onto the ground before he leaves the ground. (He is grounded until the 5th frame of his jump)