I go shopping either on Monday or Tuesdays.

My favourite sport is either football or basketball.

Hi Tess, because you speak Czech, you might find this website useful:

<a href="https://www.helpforenglish.cz/article/2008091604-slovicka-either-neither">https://www.helpforenglish.cz/article/2008091604-slovicka-either-neither</a>;

It explains the use of "either" very well and you can find many different examples there.

Hope this helps.

You have only two options either you can go out or you can stay at home.
You can either play basketball or football.