Yasuo is a very complex champion, so its going to take a while to really become consistently successful on him. He's actually my most champion in recent years and I'm still learning things with him. This said, imo the simplest to understand and implement thing that will immediately improve your Yasuo games is this: prioritize farming over fighting, especially in midgame. Yasuo still has a very good late game (not as crazy as it once was), so it's really important for you to get your items and get built if you want to be able to impact your games. Yasuo is also extremely good in a sidelane during midgame as he's difficult to outduel at this stage of the game onwards (and your core build is coming to fruition by this point). He can struggle quite a bit with teamfighting at this stage of the game because he's extremely fragile for a melee character. His core build has to be almost entirely damage and that leaves his with just his base defensive stats, which are not really any better than most ranged champions.
There's a ton of smaller things I've learned over time from playing him that I could share and bit I'm about to type out an entire article here. If you want, I'd be happy to coach you on what I know about Yasuo.