if I want a future with programming?
Knowing languages is great, however that doesn't necessarily make you a great programmer.
HTML and CSS for starters are only markup languages, not programming languages. Java, however, is.
Programming is so much more than simply coding. It's a way of thinking. It's the ability to analyze a problem, decide what tools are best to solve said problem, and then use a programming language to solve that.
If you really want to become great, and expand your knowledge dramatically, I'd advise the following.
I'll make a guess based on your profile that you're fairly young. And that's great because it means you've got time.
Here you'll find some excellent books and videos about Computer Science, and thus programming also. If you take a look at the book "Structure and Interpretation of Computer Programs", this is hosted on the MIT website, I'd trust it's a very good source for knowledge.
Take a look at that, and if you're clever you'll do things right.
Another way would be to simply learn programming languages and figure things out on a try and error basis. That could work, but you won't know as much as if you go through all these books and videos.
EDIT: I have absolutely zero knowledge of the gaming industry, couldn't even tell you what languages they use. Regardless, make of my post what you will, but if you want a future, here's one way to do it.
its what? what I mean by that is my friends want to start a gaming company with me they do the design stuff and I do all the background stuff
Here's my full answer.
p.s. I am 15 so this is me also thinking about my future
15 is great, I wish I was 15 again and made all the right decisions. Anyways.
I also had projects with friends at that age. But if you want my 2 cents, it's too soon. You won't simply be able to create a gaming company and make a great product just because you think it's cool.
You will be able to do it, and hopefully you might end up being one of the best. But if you wanna make it right, teach yourself everything you can first, to truly master programming and everything else around it.
The book I referred to, that's college-level stuff. This is what I meant by you've got time. Be ahead of all the others and you'll do great. These lessons are a lot to take, and you won't be able to just intake everything in one go.
Do a 2 hour session a day if you can, you'll go through it all in a couple years (yes, I know how that sounds. you probably want to make things happen right here, right now, but that's not how it works).
So, learn this if you can, and keep practicing coding on the side. You'll be way ahead of everyone else, considering your age.
Best of luck!