Alright yo, here goes. Falcon is a tough matchup for ganon, but DEFINITELY winnable, by a long shot. Some things to know:
your bair beats his nair
your bair beats his bair (occasionally trades)
your bair can beat knee. It's all based on the spacing
your fair beats knee
your fair trades with nair 90% of the time, but can beat it if your spacing is on point
your uair trades with nair, but can beat it if you predict a nair and uair prematurely
This matchup is all about grabs, and they're extremely easy to get actually. Just crouch cancel his nair and either jab>grab or just grab. Seriously. Then read ACE's tech chasing thread, it's more than good enough for you to see how to tech chase.
Edge guarding is simple, just bair or uair if they recover high or do the reverse uair spike if they recover from below stage. Once he's off, he's not coming back on.
Vs. aggro falcons, just dash dance, wait for him to approach and either throw out an upward angled ftilt (good because it causes knock down at low percents) or just crouch and then grab after he nairs.
For campy falcons, just eat that space. I know it's scary, but don't throw out a move, be patient. Just run in and crouch every now and then to see what he does. Dash dance heavy falcons are easy, perfect waveland into grab, jab, or ftilt. That'll teach them that dash dancing is not as safe as it seems.
I'll probably add more later.