Welcome @ K2!
The K2 Combo was also for me the first Creality printer and I have been printing before also with Prusa, switched last year to Orca (which I still use for Bambu and Qidi printer’s) but use now on K2 Creality Print V6.latest. The reason is that it handles and integrates the CFS as well as calibration when sending to the printer. It also displays printer data in progress including camera.
Martin mentioned his PETG problem which I cannot share in general, I have out of 100’s of filaments only two very special PETG which require small additional Z-offset (~0.015 mm).
The most important thing is to dial in filament parameters like print and bed temperature, flow rate and PA and also cooling as well as most important max flow rate.
The genera settings of Creality are very bad I have to say and I practically use them only on first prints for new filaments to run first test but after first calibration I use my own filament profile then.
@Martin_Prent , if you set bed temp to 75° in filament for first layer and switch on calibration in CP6 when sending/printing file to printer you will have the bed mesh also at 75°!
In general, I am very happy with the printer, I had only one failed print in last month and this was completely my mistake because I 4got to enable brim and support! I posted here how my print settings are most of the time.