What project to do as I'm beginner and I want to learn all this stuff?

Hi guys,

I love video games and by this I thought I'd like to be game creator in the future. I found Unity to start, to do something and learn, of course, because I knew this engine from assassin's creed and I learned this is free engine. I'd like to create 3D Games instead 2D Games. About scripting I'd rather writing in C# instead of Java because I heard much from different people and sites that C# is more popular than Java and it's easier to find something easier as well. I made one game which is about collecting keys so I know a little bit about that stuff. If someone would like to check this game then you can notice link below to download. However, I don't have any idea what to do next and in the most important thing - something what would learn me this creating, programmic and so on stuff. I learned kinda while making this game but not much. By the way it took me about 50 hours. So, what to do next and next to become good, really good and amazing game creator in the future? I do really like to do this stuff as it's my interesting but I don't know how to take this all on my own. I don't have any friend who is making something in this program and in C# so it is a bit of harder yet. I know I can always ask about something here but it's too bad (I think) because sometimes I would have to do even more then 10 topics per day so you know, about sometimes every single thing etc. I have never created anything so I'm newbie.

Here you can download this game which I was talking about (I know this game has been made in other language then English (exactly in Polish because it was trying by my Polish friends so I made it in this language) but there are only couple of words so I think that won't be a problem): https://www.wetransfer.com/downloads/875ebd6723fcef8eeac85c231a29bcd220160531144304/ed589c