Working with Textures

Maybe my question is stupid, but I do not know how to achieve this in the editor, so that the texture does not stretch to the whole object if the sizes and proportions of the texture and the object do not match.
You need to create a texture for a simple object (rectangle, wall).

It is necessary to impose a texture on a simple object (rectangle, wall).
There is a ready object. How to calculate the size of an object in pixels, that would create a texture without removing the object from the editor? Are there any standard calculations and proportions? Let’s say I’m using the 1x1 world scale. How many pixels in one “game” meter?

I think what you are looking for is tiling? In your material, add a texture coordinate and connect that up to your image. Change the tiling in details.