I want to create grid withs cards that looks like on photo, every card have text in it.
What would be better to make , all square or rectangular cards ?
Rectangular. A square grid can create an optical illusion called the Hermann grid illusion. https://en.m.wikipedia.org/wiki/Grid_illusion
The squares of this size will not be readable for users, there is too much of them in the grid to keep users interested. I suggest you increase the size of cards and decrease the amount of cards per screen to 8 or 12 max. Consider some color coding to avoid cards looking homogenous.
A square grid feels nice and organized.
But as Martijn said, (small amounts of text) tend to be wider than they are tall. Look at google results, at the replies on this website, at the windows start menu, etcetera. So you'll get better results for text if you use rectangular grid.
As for your image in your post, 7x7 is a weird number - but you probably just googled that as an example, right?