Im not veteran but maybe this helps, think of a small prototype skeleton of a game, dont imagine a full blown world with 1000 features, think small, one of my prototypes is where i made a flying ship around the landscape i spent over a week trying to get decent flying controls, it still sucks to this day but i learned a **** lot, then i tried to add projectiles and so on, and you have to research every little step throughout tutorials/answer hub/forums, try making various small blueprints that do random things, also learn how to pass data from one blueprint to another using interfaces so on.
And dont be sad that you cant remember things off the top of your head, thats not a goal for anyone, its all about learning the concepts.
When you make toturials dont just copy pasta everything and pretend you understand what the guy said in the video, insert small ideas while doing those tutorials, so a tutorial just showed you how to shoot a laser gun? before moving any further try to see if you can make pulsating laser beams, or make them go dimmer over the distance, thats how i learn at least, its very hard and takes time, i did this silly mistake with unity, i tought i would just watch tutorials one after another and then i would try make a game, lol fail i ended up quitting after a couple of months without creating anything, until UE4 reignited my passion and i tried a different aproach.
Do not try to do C++ if you are a beginner, do only blueprints and learn C++ basics separately but spend most time with blueprints and see how they interact etc, its quite easy to transfer code from BP to C++ once you know both.
Dont give up, it takes a couple years to become really good at this.