How to customize the appearance in WordPress?

Question

WordPress

Hello!
I've been using joomla all my life, I wanted to try WP, I'm trying to figure out how to make the picture be in a position like here wp1.oda-turbaza.znjg1.spectrum.myjino.ru/wp-conten... .
I put this shalbon and I can’t understand where to press, it seems like I poked everything.
Thank you.

Answer 1

Admin->Posts->Your post->lower right corner->Set thumbnail
If this is what I think and this picture is from the post -)))