Need help with adding/fixing rigging to my model

Welcome.
I have a problem with adding rigging to my model, mayby because i’m not good at this. I added rigging to it but I have a problem with rear legs of it when i trying to make sitting or lying pisition - possible by bad weight pait. The model was created for 3d printing not for animation - I wanted to add rigging to simplyfy changing poses and didn’t ended very well. I’m looking out for someone who would help me fix it, because I know that I’m not good in it. I’m also not perfect in moddeling but I beggining cathing it.

Link to blend file:

(edit)

Bassicly i wanted to make sitting pose like that for example:

HI, you could use the Meta Rig and rigify wolf rig:

It helped, big thanks it works much better.
But right now i have another issue i began making that pose in mirroring mode and that happend:

I’ve tryed to find reason why that’s happend but it isn’t problem on side of model and rigging
does some way to fix it?

(edit)

I’ve solved that - weights was incorrectly painted.

And additionaly i have problem with paws and claws that weird shaped after it.