Friend’s daughter needing online resources for learning Linux and coding

I'm giving a friend's daughter a laptop loaded with Linux Mint.
Can anyone recommend a reddit sub (or other online forum) that's friendly, kind, and suitable for a high school girl learning Linux and coding? I'm not familiar with this sub, not sure how supportive and moderated it is (no shade intended, just not every place on reddit might be suitable for a highschooler who might be shy or uncertain)