So I have been wanting to make games for a while but I just did not understand most of the Blueprint nodes I need
if your taking a course on UE4 then i would start with the tutorials made by epic. they are a bit old in that they were made with older versions but the basics all still apply. below i will link a few video playlists that i would start with. beyond that just watch tutorials on anything that catches your eye then modify and adapt the scripts so you learn how they work. as for knowing which node there are and which ones to use, well that comes from experience. the more you use blueprint and the more you learn the more you will know and understand. theres no comprehensive list of node that i know of but you can usually find what you need by googling and looking through the docs.
What ThompsonN13 said. In addition to the links he provided I would add there are some good tutorial “series” that kind of walk through the basics of creating gameplay in blueprints on YouTube that aren’t official from Unreal. I found these more helpful since the official ones I feel were a bit longer and have more detail about the engine itself and how it runs (not that it is a bad thing but when you are starting out those details probably aren’t that helpful until you kind of have a feel for what they are talking about). I recently started a beginner tutorial series along with a bunch of other random tutorials I have made geared towards beginners you can check out below.
I would also recommend the following other YouTube channels (they are a bit more established so they have more content than I do at the moment)
Dean Ashford (good for graphics/particle systems/materials and some basic gameplay, unfortunately retired from tutorials but still lots of good info)
Virtus (been around for a while, lot’s of good tutorial series, still making them too)
To add to what nebula said i would suggest titanic games youtube channel.