As a veteran from the other side of the career spectrum (40 years freelancing, though most of it while working full time) I have a few thoughts for you, and the others here who responded…
You wrote: So, oh wise ones, where did you find your tribe when you started freelance writing? How did you connect with other writers who were chasing dreams similar to yours? Did you have a mentor? I would love to have a mentor who could help guide me through this foreign place I have found myself in.
First comment: Things have changed a LOT since when I first started. There was no internet back then.
Second comment: Life is a LOT longer than you can possibly imagine right now if you are young. If you really want to be a writer (or I should say, if being a writer is your calling) and you keep at it, I believe one day you will look back and be amazed at what you have accomplished.
Third: In the beginning I joined a writers group and went to a couple of writers conferences where I learned a LOT of fundamental things that helped get me on track to query professionally and present myself professionally.
Fourth: I also met my mentor at the writers group and he made all the difference in getting me up to speed faster. Helped improve my editing and writing as well as seeing the possibilities of writing.
So yes, I had a mentor. I found mine at a writers group, and I am confident that there are writers groups in nearly any city of modest size.
I personally find Fiverr and bidding on Upwork to feel demeaning. I disliked the competition and all that bidding stuff.
For freelance writers starting out, getting bylines is really valuable. Print is not dead. Nearly every community has small newspapers and weeklies. They don’t pay a lot but give you a chance to build the portfolio. ALSO, you will find through having your work edited that usually it gets improved.
Much more can be said, but this is a start.