Does anyone have some gunpla they've put together recently, or that they're working on?
Here's an old RS-178 MKII PG kit I assembled recently. Still deciding how I want to detail him, but as my first PG the level of detail and articulation is really cool.
I know of blogs like Good Guy Dan that have a lot of gunpla tutorials; the set for the HG Sinanju looks like it touches on a lot of what you're looking for.
Personally I don't have a particular go to place though, most of the time if I have a specific question on like thinning ratios or how to use something I search discord or the first few pages of Google. A lot of like military modeling forums out there where the advice still applies to gunpla, stuff like that.