Don't even know where to start? Check out these Resources.
YouTube cybersecurity content is largely bloateed with green-text and hoodie skid content, but there are some really good YouTubers on there like LiveOverflow (Website) and John Hammond (Discord & Website). Obviously this isn't all of them, but those two are some of the best.
Creation & Solving Tools
If you're looking to learn how to create or solve CTF questions, Apsdehal on GitHub has an AMAZING tool list here. If you're looking to do some PWN style challenges, Kali Linux and Parrot OS are very helpful.