Hello Fabian,
I do not have experience with that kind of filament, I actually use cheaper local material but it looks like you temperature is too high causing the material to melt too much as well as not sticking properly to the bed.
ABS would usually require 250C not more, you did not mention the properties you made the above but the strings your getting all over can identify that.
Along with that I can tell you’re bed is not hot enough thus your bottom layer is not flat.
Three factors effect the bottom layer and the whole process along with that that could also benefit your print quality that looks like they do.
1. Bed temp, if not hot enough (can probably use 90-100C easy).
2. Z height, use the Z height adjustment from the Prusa menu and make sure the gap is as much as a paper thickness, not more. A good way to inspect it is when you use the Prusa Slicer it draws a line prior each print in the from of the machine, the line should be like in the manual you got with the printer, sunk but not grooved.
3. probably most important, reduce the first layer speed, assuming yo are using the Prusa Slicer predefined params, reduce the first layer speed to between 20-40% small areas can use 60% as set, bigger areas 40% and big areas 20%.
You know your first layer is good once it is flat and all you can see is lines of the filament previously drawn, if it looks like your ship it is not good, as you can see there are gaps between the filament lines and your adhesion to the bed is not good.
I had that problem a while ago and once understood the first layer issue, all my problems were over
