Supervisor doesn't give me a chance to contribute more and gives himself first authorship, how to approach this?
Well, so let me phrase it this way: Your professor had the original idea (which you then fleshed out and executed) and then did the most difficult parts of the writing. I typically see that what students struggle most with are introductions, providing context, the literature review, and forming conclusions. If that is true for you as well, then the parts your professor wrote would have likely taken you a long time to do. If you see it this way, then it is, at least, not inappropriate that your professor would be the first author.

What I think most people would probably agree with you is that doing all of the writing him/herself is a poor way of teaching you how to do it. Ultimately, we educate students because we want them to become knowledgeable and independent, and that can only happen if we teach them how to do it, not do it ourselves. If your professor is still young, you might want to simply ask to be included in the writing part in the future, and say that you'd like that to happen because you'd like to learn how to do it.