Just a general question for people who are playing more than just occasionally. I'm trying to learn the game enough to at least take part in local events/tournaments as a way to develop a hobbie and meet people, but I'm not sure how to go from just dabbling to actually becoming decent.
I went through the "Art of Smash" video series on Youtube, and now I just play online in public arenas with random characters to get familiar with them, but it doesn't feel like it's really helping get better, mainly because of the online being so bad (even on a 2Gbps fibre connection it feels like I'm playing in slomo).
What do you guys do to become better?
Find a training partner to play against in person is the best way. Until then, focus on movement and execution.
That said, just go to an event and play people. No matter when you start going to events and no matter how much practice you put in beforehand, you are extremely likely to got bodied. And that's 100% okay. Pretty much everyone has gone through that same experience. It doesn't have to be a tournament. A simple smashfest near you is perfect for this. You'll lose most/every game at first, but you'll be able to talk to the people beating you and get advice so you'll improve much faster.
Just go in with an "I'm new but looking to practice and learn" mentality. Most smashers I've met are pretty receptive to that attitude.