With the exception of BoomerZ, everyone in this thread is dead fucking wrong.
Your job is not to create an art style, it is to find the art style you already have.
And that is something that happens on its own, over time, with or without your input.
So don't worry about it. Don't even think about it.
Seriously, stop thinking about it. It's not worth caring about. This grand esoteric concept of 'having an art style' is something I see so damn many young creators get hung up on. Hell, I got hung up on the idea myself when I was but a wee lad, and it actively slowed my growth and hurt my mental state.
I was so wrapped up in the idea of 'having an art style' that I didn't focus on my fundamentals or storytelling. Looking back now, I had an art style from day one. Literally every single person already has one built into their brains from birth. Understanding, refining, and developing that style is a skill that you can train and exercise to improve, but you don't just 'not have an art style'. That's akin to not having food you like or music you enjoy.
As soon as you are capable of differentiating one thing from another and assigning it a value judgment, you have an art style, so get the fuck over it.
Work on fundamentals, learn things like anatomy, form, perspective, movement, expression, texture, and composition. All of those things will serve you much better as things to focus on, and your precious exalted 'style' will begin to present itself naturally as you practice.
And you should definitely practice.
Like a lot.
A lot a lot.
Draw stuff. Keep drawing stuff, Draw until you've filled your entire sketchbook or canvas or whatever, and then draw some fucking more.
If you want to get better at doing a thing, then you have to do said thing. The more you do it, the more you'll improve. Find other people who are doing what you want to do better than you can do it, and then listen to them. Draw something, then critically analyze it to see where you fucked up, then try it again and see if you can do better on the next attempt.
Forget about 'creating' an art style, don't even worry about 'finding' the style you already have. It matters about 1/100th as much as you think it does in the long run, and you'll find it anyways along the way, so just don't think about it.