Peertube is the Fediverse equivalent of YouTube, the Fediverse being what Lemmy (where you are), Kbin (where I am) etc. are also a part of.

As far as I'm aware, it's a matter of finding an instance you resonate with, create an account and share away.

Do bear in mind that since it's the Fediverse, Peertube instances aren't usually backed by a large organisation with bags of cash, so if you can afford to donate to your instance, at least consider doing so.

I'd also recommend not using Peertube as a be-all-end-all storage for your videos. Always keep a copy for yourself. People do this with YouTube and they shouldn't unless they're OK with suddenly and forever losing that content at some unspecified future date. The same can happen with PeerTube, but the reasons are likely to be different (instance closing rather than unexpected account deletion).

Corporation-backed video hosts include: Twitch, Dailymotion and Vimeo. You could probably also host on Facebook. While these are options, they might make you feel as unclean as I did typing that out.