My one-tweet Mastodon starter advice:
1. Pick a server where people are likely to post generally about stuff you're most interested in.
2. Follow interesting people on other servers, who will boost interesting stuff into your home feed. THEY are your algorithm.
This is true to a certain extent.
I must VERY MUCH recommend the use of Lists of people because then you can have a custom thread of people, e.g. you're on "Interesting people" because you drop good knowledge. It was only when I was wondering where you all were that I clicked on said list and was like "New Timeline!"
John Bull
PJ "Vote Green" Coffey
Oz Grrl