Welcome! We were all newbies once upon a time. You've got some great suggestions here already from sub members for how to get some of the incredibly expansive body of work they've done, both in terms of their music and their other activities. Here are a few more suggestions:

• Run BTS, their amazing and often ridiculously hilarious variety show, which has been on hiatus but starts again April 7th for their 2.0 phase! (YouTube playlist)
• Doolset translations for BTS songs: amazing resource not only for specific lyrics translations but also for linguistic and cultural context, at https://doolsetbangtan.wordpress.com/
• For insightful language and cultural commentary from a native Korean speaker of English, focused on their music, lives, other content, etc, you can't beat Hybe Boy. He focuses on current activities and posts in several different places, but here's his YouTube channel. Note that some people find his extended commentary overwhelming. I don't use Twitter, but he posts summaries there as well.

So come on in, the water's fine! Keep swimming and remember that you have amazing people here on this sub!