From where should I Start?

Hello, all! This is my first post after just joining this discussion, so please forgive me and provide kind assistance if I have posted to the wrong subsection!

I am new here but a real enthusiast and loving this community so far. I have a background in teaching coding and in education and feel I could help with documentation, at least for starters.

As a new member in this forum and wish to share and gain some knowledge. I am looking forward to create my own discussion to resolve my query and gain some knowledge though I have taken part in various discussion which is definitely helped me a lot.

Also what category should be taken depends on what factors? 

Thankyou in advance.