If you have just installed Mastodon and don't know where to start to find people to follow a good idea is to try and check other users follows and one by one try to see if you find someone to follow.
Alternatively you can go to https://communitywiki.org/trunk and do the same on the categories that interest you.
If you are lazy and don't want to look up one by one, I created a little script to generate a csv from Trunk categories: https://hugo.gameiro.pt/trunk-to-csv/ that you can then import in Mastodon.
@feditips OK, I have included @FediFollows on both my 'Finding people to follow on Mastodon' post https://masto.host/finding-people-to-follow-on-mastodon/ and on my 'First steps after installing a Mastodon server' guide: https://masto.host/mastodon-server-first-steps/
I completely forgot to include FediFollow when I wrote those. Sorry and again thanks for reminding me.