Gh5 is a lot of bang-for-buck. Can't think of anything much better to start out on.

I think hollywood blackmagic will bloom a lot. My 1/2 definitely gives it a strong bloom.
Lenses - some of the Xeens bloom wide open. I think the 14mm but that's very wide. I test a butt-load of 'em here if you're bored enough to watch haha: https://www.youtube.com/watch?v=mgbHlvFm6mk&t=410s

Thank you Patrick, and you as well!

Shoot lenses that bloom more wide open, and filters will do a great job for that as well. Glimmer glass, Hollywood black magic, promist. Stronger it is the more bloom effect. Any of those at like a 1/2 or more should produce that look quite strongly.

Like above, I think it definitely depends on the shoot. But overall I'd say Alexa Mini. Really hard to beat that camera (in my opinion). I shoot on the VariCam LT, that's also a really nice option many sleep on.
I think someone mentioned it above but lenses are key, too. Lenses and lights. Those will give your film more characteristic than the choice of camera, so that's something to look at.

If you want to learn I'd start by reading interviews like this one, listening to podcasts, watching behind the scenes, reading, but then of course #1 most importantly...go out and shoot. The building blocks of learning your own style is by experience. Shoot a ton of different stuff, see what you like and don't like, learn from your mistakes. The more you the shoot, the more you will learn.