Does anyone have tips against Falcons that wait for you to make a move first then react to whatever you do?
Kimi, this doesn't sound like much of a Falcon problem, as much as a neutral-game problem in general. There are a few things you should definitely take into consideration while playing against defensive opponents, two main things being they're allowing you more free stage control, and nobody can perfectly react to everything (especially with Yoshi twitch movements) so a reactionary play-style leads to easier baits.
When I say stage control, I mean pushing them to a corner, keeping center stage and approaching smartly without putting yourself at risk (you don't need to actually attack, just threaten space). A defensive player that's not looking to engage will continue dashdancing waiting for something to happen, until you've pressured them to make their own bad decisions ie retreating to platforms, or making their own approaching mistakes you can either avoid/punish, DJCC, parry punish, whatever. In other words, get in close with non-commital options to make them feel uneasy and switch away from their preferred gameplan. For falcon in general, understand that your ground game is much more solid than his in terms of everything but grabs, so know he'll want to punish with either an aerial, or grab, both of which are stuffable by different things. Just be patient, and approach mostly grounded until you're in a situation where going to the air isn't going to be as easily punishable (but that doesn't mean still staying grounded is bad either).
Yoshi is actually a great character for playing against a lot of defensive playstyles, like Marth or Falcon (defensive foxs though... ehhhh) because of all of his movement options. Like I said nobody can react perfectly to anything, and with a lot of the stuff Yoshi has at his disposal to really mess up spacing, and mess up the opponents anticipation of your movement, it's relatively easy to feint your way into your opponents mind and defenses. Try doing things like overextending dash into DJL to reset into standing, where you can either throw out a f-tilt wall, or restart your dashdance immediately to continue pressing stage, try using DJC back baits, and definitely don't take the new auto-cancel D-air tricks lightly, please, they are extremely useful. I've punished many people myself with things like full jump RDJC d-air cancel, and punished as they attempted to follow up to where they expected me to be. It's all a very mental game where you have to understand what they are waiting for, and how they're looking to punish once they react.
(Also this is a personal thing I've noticed about your playstyle, you're very formulaic in your movement, and it's easy to read you and know what you want to do, especially when coming down from platforms. Try adding in some DJC-dair off of platforms instead of always going for the more aggressive options. Every lower platform of the neutral stages can be run off, and immediately RDJC d-air cancel to get the movement of your RDJC, with no landing lag to grab immediately, or just dash away, start DJC n-air pressure, anything you want, the possibilities are endless, so stop just f-airing. This gives you an option to mix up on shields, make them guess f-air or d-air cancel so you have a better chance of landing the f-airs when you do decide to go with that option, since they know you have an option against shields with the d-air cancels)
I dunno if that all made sense, but for the past like 3 years or so, I've been playing more traditional fighters taking a break from melee, so I tend to try to think more in terms of spatial and mental awareness now. One of the big things I try to tell people around my area that are trying to get better (and you are far better than the people I normally get to play with, probably even me xD) is that if the opponent knows what you want to/are going to do, then you've pretty much already lost. So keep that in mind. Hope that helped, but it probably didn't. I'm bad.