Can I add music to my Apple Watch without a iPhone?

Apparently, i want to add music to my Apple Watch. Options are that I get Apple Music subscription, which costs money, or I can sync apple id's to my phone. Here are the problems

I have no Phone, not for a while.

I don't want to waste money on music which I don't like a lot

I like music from youtube, something that fails to exist on Apple Watch

I have the Family sharing app, making it not possible to do it.

Is there a way to do it on my computer, while not using any phones or anything related to family sharing.

[Re-Titled by Moderator]