use uYouEnhanced (it’s iOS only and on github). gotta build it yourself with your own decrypted youtube IPA. haven’t seen an ad in years because of it. it also includes sponsorblock and free downloads
due to apple’s stupid side loading policies, you gotta sideload this through a service like AltStore or Sideloadly so you can actually launch the app. i personally recommend sideloadly because they allow 1 more app to be signed than altstore, and they let you enable file permissions for apps you download
i’m not sure. most people at my school use a laptop at their main computer, so they couldn’t use an ubuntu DVD anyways. i personally prefer dual boot over single boot