>>It's hard for me to answer questions specifically, so can I just tell about myself in a free form? <<

That's fine. Thank you for mentioning that. I have added a note to the opening that invites people to do this if they want.

>>I'm agender. This means that I don't belong to any gender. However, I prefer to use he/him pronouns.<<

I'm genderqueer and don't have a strong pronoun preference.

>> I don't want to talk about where I live exactly. I prefer to dream that I live somewhere in an unreal world, because I'm bored to live in reality.<<

I spend a lot of time in other universes because this society is horrid.

>>However, there are some things that can somehow make me happy. I like to read books. I have moments when I can get really carried away by a book and spend whole days on it.<<

That's good.

>>I also have a houseplant. It’s a gift. I can’t say that I know how to take care of plants. It’s probably not really my thing.<<

First, identify what plant it is, because they have different needs. If you're not sure, there are resources.

https://www.portlandnursery.com/houseplants/houseplants

https://www.earth.com/earthpedia-articles/houseplant-identification-101/

https://houseplantresourcecenter.com/2022/05/houseplant-identification-tips-to-id-your-mystery-houseplant/

>> But this will probably be rare, since I am not in the mood to write anything right now.<<

You can also post pictures, links, videos, etc. These are often less work than writing.

>>English is not my native language. I write in English to practice it and I like this language. So I apologize in advance if there are any mistakes in my text.<<

You're doing quite well with it.