So I'm trying to up my photo game from nice cell phone cameras to something real. I mostly am shooting in very dark rooms with little natural light and limited artificial light.

I have heard mirrorless is better for this sort of stuff? And I think Sony A7's are still the top mirrorless?

What is a good one that I can get for like $600-1000usd used, as I will be breaking them decently often and don't want to be buying top of the line to destroy them.

What type of lense would be optimal for this sort of stuff? Any other things I need to be looking for?