The OP wrote this as a learning exercise. With the goal of learning in mind, I would suggest that it's probably best for the OP to go and read as much code as they possibly can, no matter the license!
Perhaps, but lawyers can ruin your life. If you ask me, it's a travesty that the law is so complex nobody in this thread can agree if this is good advice or paranoia run out of control. That's the world lawyers have created for us, and like it or not, we live in their world.
The OP wrote this as a learning exercise. With the goal of learning in mind, I would suggest that it's probably best for the OP to go and read as much code as they possibly can, no matter the license!