Just keep doing it! Way to go! Cheers. Keep it up. Congratulations!

Don't get too concerned, even the English speaking amongst us, struggled when we first started to write. For many it, would of been the first time since school.

One of the things about the WA experience is that we are all here to learn, and help each other.

There are so many resources to help us, Site content for example has a checker built in.

Another resource that many of us use is, Grammarly.

Best wishes you will do okay, you have just written this post, if we chip away we get better as we go.

Your writing will improve in time if you keep going on, I'm sure of that. You can use grammar and spell check as well and when you request site feedback (after having your website set up and running), you can get some feedback on your content as well.
Have you chosen your niche already?

Your post shows that you will be able to work in English here at WA. You can write your website in your own language and add a translation plugin. Sometimes the translations are not great but it works. As well, you can go look for a free online translation program where you can type in the content in your language and it translates... then you simply copy and paste onto you site. I have used this a lot and many of the programs work well. Happy New Year.

Your website can be in your own language. You won't be able to use some WA tools like site comments, etc.
There are also tools like Grammarly that can help you. It's a free tool but it also has a premium version.