HOW DO YOU KNOW WHERE AND WHICH COMMUNITY TO POST IN.....?????

guys I feel like a idiot !!!!!! where do I figure out where to post ????? are there selected community's??? is there a blogging section...???? I know this browser is more for "coding nerds" as some call it.. (me) butttttt I wanna figure it out and get along with yall!!!! even though I just called y'all nerds..!!!! (I want friends.)