Two excellent, in-depth guides to Mastodon, which should answer many of your questions, are here:
1. An Increasingly Less-Brief Guide to Mastodon by joyeusenoelle: https://github.com/joyeusenoelle/GuideToMastodon
2. Nikodemus' Guide to Mastodon: https://docs.google.com/document/d/1D9gfeKg_-hlsU66R-dLEvUeyMsqEfyIx2pnfUeX0t_E/edit#heading=h.j95atvlbfrn5
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