Ender 6 print settings

I got an Ender 6 a few weeks ago, but am startingt o struggle getting the prints to work. I check that the bed is level before starting any prints, but it never seems to work right. Sometimes the plastic just doesn't stick to th bed, and other times it curls up on the edges and knocks itself loose.

What's the best settings on both Cura and the printer (temperature wise) to stop this from happening?