We are at a similar stage, though I have played more 19x19 it seems.
I wrote this about how I got to 20k: Your beginnings with Go?
There might be some useful bullets in there.
The main thing I am benefitting from at the moment is Dwyrin’s “Back to Basics” series. Plus teaching games with generous SDKs, who you will easily find if you ask.
I think you might want to play a bit more 9x9 against humans to bed down those skills, before going for 19x19.
You definitely should not hold back from playing against other people. The ranking system is great for letting us all know what to expect, so you won’t be disappointing anyone. You will certainly learn more, more quickly that way.
9x9 isnt really my thing … I’d be happy to play 19x19 with you for fun and learning any time you’re ready.
GaJ