Hi guys So, I couldn't wait any longer and started printing this week even

Hi guys
So, I couldn’t wait any longer and started printing this week even though several things are not finished yet. The two big issues that I’m struggling with are the dribbling of the hot-end (although I see I can minimise it a lot if I use Slic3r) and backlash? My circles don’t look too good. Probably covered somewhere before, but how do I figure out which belts need some attention? The picture of the circles taken from the top is with the orientation from the front of the printer.