First off learn how to make reflector scary to use. This is a must against reflect characters and projectile absorption characters.SS cancels into shield meaning approaches can be countered with anything you can do out of shield. Reflector also has decent cool down meaning you can charge and bait reflector and then dash in to attempt punishes.
Fox's rush down is all about spacing because his range is no better than yours and he doesn't have any disjoints. Learning how to pivot ftilt to beat out dash attacks and grabs will change your game completely. His short hop game with nair and bair can be crouch>shield punished, and because you don't lose any options while crouched, this is a great defensive position to revert back to in neutral. It also ducks lasers so you don't need to have fear of that. I need to double check and see if crouch goes under grab, I don't think it does however.
On offense, jab is your friend. Since Fox will want to be up close too, you can use it to bop grab attempts and spot dodges. It sets up for good damage, netting more and more the higher their percent. Ftilt is one of your kill moves, clashes with all of Fox's ground moves except Dsmash(which it occasionally whiffs) so it's good to throw out if you predict an attack. Nair is your go to for damage building and general shield pressure. At around 90%, soft nair combos into usmash for the kill(70-75 with DB). At around 105% ffnair combos into uair for the kill. Grab often and keep him in the air, neither of their dairs are particularly threatening and even less so when you're on the ground.
If you knock him offstage, watch his movement before deciding what to do. If he goes low, chase after him. WFT loves being offstage and space animals have always had a linear recovering, bair, dair and header trades are in your favor so go for them when you can.
I haven't played any good Falcos yet but his moveset isn't much different from Fox, so I'd proceed similarly.