For variations on Mastodon it depends on the settings used by the admin. Glitch has lots of optional features which can be switched on or off, or adjusted. For example the character limit might be set by the admin to 1000 or much higher.
For Calckey, Akkoma etc the experience will be totally different because the software isn't based on Mastodon at all. I'm not sure how much help a guide would be compared to just having a look at their websites.