Hi!
Self-hosting seems a bit overkill for your situation but having an account somewhere can be helpful for managing your playlist and/or watch history. You can also comment/upvote videos you like with an account.
(Note that on the mobile app, you don’t need an account to manage your playlist and watch history)
Yeah!
What you should check if you want your account to be available from most platforms (instances) is that the platform you want to register on is listed on https://instances.joinpeertube.org/instances
Any platform found through JoinPeerTube website or Sepia Search is from this list.