You should have a look for capture the flags for penetration testing.
TryHackMe currently has a free Christmas program which has a beginner focus and outside of that they have a mix of free and paid for content (don't be tricked into feeling you need to pay if you just want the free content, navigate about a bit)
I've done some of the content and CTFs at HackerOne and I have heard of people liking HackTheBox too although I haven't done anything over there myself.
Hopefully that gives you some inspiration and guidance to get started!