So I've been sitting on HoI4 for awhile, figuring I'll give go soon. Can I get some advice?

So played a lot of EU4, CK3, Imperator, Vicky 3 and Stellaris...HoI4 felt left out lol

Figured I ask, what are some good starting nations? Any good "up to date" guides, videos or whatever I can check out?

Any tips or whatever?