All of the above can be useful, but don’t get too hung up on YouTube videos about proper playing technique. You play whatever way works best for you. Many BCers here started off before the internet existed and all we had were a few thin books, probably now out of print, and our eyes and ears. You therefore have it relatively easy, but use it wisely. If you want a teacher, get a proper bass teacher, not a guitarist. Learn how to set up your own instrument, and this is where the internet can be useful, but also confusing. Again, eyes and ears. Good luck, stick around, most don’t bite.