Do you make money online and if so, how?

I am 19 years old and working 2 part time jobs paying me barely 1k a month I’m stuck in a empty feeling that I have all this free time and not using it for anything of value (just playing games or hanging around). I feel like if I did something significant which ideally would include making money I wouldn’t feel so bad for just waiting this half year before my University studies begin. I just can’t seem to find any actual methods or they are too complicated. For example making a online store. Seems easy on paper and has a lot of tools to help you along the way but finding a product is difficult and building a store is difficult. What is something that guarantees some sort of success if I just work. For example I answer some surveys here and there for a couple bucks. If it would work better and I could do it more I would answer surveys all day just to earn 100 extra that day. Help me out guys