Hi,
I'd like to ask. How can I set my own resolution of image (svg). I need this because of snapping grid. I need rectangular image. E.g. 500x500.

Ok, when you say "resolution" is this for the purpose of printing?

You can create a grid of almost any unit size.

If you need to change the size of the page, you can do that in Document Properties.

I'm not at all clear what you're asking

thanks a lot. I didn't notice that. Yes, I mean Document properties.
But is possible to create a new template - similar to "Web_banner_468*60" "Icon_48x48" ... (to create new item in FIle → New → My_own_resolution 13x71 ) ?

Yes.
Down towards the bottom of this thread, I wrote instructions
viewtopic.php?f=6&t=162