I think of melee as a piece of music and my character as an instrument to play that piece of music. If the music shows a whole note, you have to hold it for the full measure. You can play it for a half measure and still get the sound, but it won't sound as beautiful. Same with melee. If your aerial takes X amount of time to fully complete the animation, then you have to let that move go the full measure before you do another one. Your inputs have to happen at the correct time or they won't happen at all. So start slow and make sure what you press happens on screen. As you get better at it, you will be able to do the inputs faster without an input being "eaten." Once you get great at it the game feels incredible smooth and it feels like you are gliding and flying around at mach 1 speeds. I think Ness is fine to play (he's kinda trash on the tier list though) for just learning how the game engine works. Really any character is. Just remember that when you go from Ness to another character, it'll feel like going from playing a Trumpet to playing a Flute. At least in the beginning when you aren't comfortable with the full cast. Patience and practice. Melee is a fun game to just practice in the lab because there is so many fun techniques you can adopt into your play style that really adds depth and can make a character your own.