If you have no experience with Blueprint at all (and presumably not with programming, either) your best bet is to start small. You won’t understand how Blueprint works until you’ve tried it yourself.
Personally, I’ve got coding experience, but because I was new to Blueprints I still started with the basic tutorials. Not just watching them, but following along, recreating the project. Sometimes I got stuck, then I had to do some research or experiment or ask. Sometimes I would tweak the project (in very small ways) how I liked it better. If I did that during the tutorial, that would sometimes cause problems at a later step, so I’d have to adjust the necessary steps to match my own changes. In the end I had about a dozen tutorial projects lying around. That taught me heaps about UE4.
After that, when it came to building an actual game from scratch, I had it easier than you because I’m working in a small team and seeing how we’re all new to UE4, we can discuss our problems and learn from each other. Then again, you also can ask questions here. 