Is important to know how to make a game without a Java engine?

Hey guys, im pretty new in Java(like 1 or 2 weeks), and i started to see the basic java game programming series of a YouTube channel called “ForeignGuyMike” i dont understand at all, im searching every thing i don’t know(and sometimes i still not understanding that) and some simple things like set the FPS on my game is complicated to understand(and more because my main language isn’t english), and i know using a framework/engine to make games in Java makes the things more easy, but i want to learn correctly Java for my future programming, and i don’t know what to do. ??? ??? ??? ???