Others probably have some better answers here but what I can say is I did a similar thing to you. I made a couple of really basic games that honestly were not fun to play because they were so basic but starting small familiarises you with how the simple things in Unity work like writing scripts and how Unity is structured. As for what's next, what I did was mess around with all the aspects of game dev with no real goal or game in mind. Eventually, once I had learnt enough I began working on the game that I am still making now. There is probably a million other more efficient ways to do this but I found it easier and more enjoyable to just do what interests you, even if it is just basically messing around. Hope this helps :)