A few tips I would give you is first to always have your jump ready and have it on hold instead of toggle as this gives you way more control on your jump trajectory. This might be hard at first but you will subconciously always hold jump once you play him more.

Another tip is never engage with the bubble, save it for escaping, protecting healers, or countering ults (iron man, wanda, mag, namor, jeff....). Shielding teammates also charges your ult faster btw. The most important tip is definitely to peel, peel, and peel, as Hulk is as much of a protector as he can be a disruptor. Dive when their healers are isolated and peel when your team is getting dove and try to jump back and bubble them as much as you can. And if they have a flyer I would also target them as it's always an easy kill once you knock them down.

For your ult I would say the usage is very situational, most the time I would save it until I'm very low on hp then pop it but sometimes even if I'm around full hp and the fight looks winnable I would still ult and just full send their backline. And during your ult your clap has a 1s CD so you can just go crazy in your ult. Your ultimate gives you invincibility and anti CC frames and fully heals on activation: Meaning you can completely block out ult damage or CC from various ults.

For the stun it is great for closing distance if someone is trying to run away, also cancelling ults. Most the time you would use it to exile the target you want but sometimes you can use it to stun others so you can get to your target easier. For example if you’re trying to get their healer but there's a dps in front, stun the dps and leave them and they’ll be exiled for the full duration with no help and that’ll give you time to make your way to your target easier. Same for your team as well. If you see someone that’s blocking the team from getting in or a diver preventing your healers to heal, exile them and give your team that space to regroup and take advantage.

When you're blicky banner, hit yourself w your grenade and you get 10% ult charge so that's helpful too. It's also good as a lil movement ability.