First i would disl down your scope for making your first game, make something super simple first. As for how much c++ you need, you can make a game with zeo if you wanted. Blueprints have a ton of functionality and can be used to create entire games. So blueprints are a good and easy way to start for new devs and people just startung with programming. As always ghough there is a but, c++ is generally a but more versitle since its not limited by what nodes the devs have created. From what i know blueprint basically calls c++ script in the background. This leads to one more point, c++ if written well is a bit lighter and more optimized that is to say theres a bit less overhead and will perform a bit better.