@Aeroxx_creative
Although you can't import the gCode, you can open the file using a 'text editor' and read the header and/or translate the gcode instructions.
These are just a few extracts from the Cat gCode:-
; printMaterial,PLA
; printQuality,High
...
; layerHeight,0.1
; useRaft,1
...
; infillPercentage,15

M140 S45 ;bed temp =45'C
M190 S45
M104 S200 T0 ;nozzle temp = 200'C

I hope this helps.

@Oldsubguy86 If you are getting a 'change filament' message, although you have not run out of filament, then it is a problem with the filament sensor and/or sensor wiring. Some people have reported problems with intermittent sensors on this forum.

I have bypassed the sensor on my machine (https://forum.creality.com/topic/2004/creality-cr-10-too-much-friction-resistance-in-the-filament-detector) so you could do the same (...just so that you can get on with printing a few objects and make sure that there are no other problems with your machine) while you look for a solution.

When I say "bypassed" I mean I have cut a short length of filament and pushed it into the filament sensor, and then run the filament directly into the print-head/extruder.

@OneFlyBear It could be under extrusion.
Try printing a calibration cube like this one: https://www.thingiverse.com/thing:1278865 and then carefully check dimensions and print quality. You probably need Vernier Calipers to properly check dimensions.

@telephasic That's a good explanation.
I'm amused by the idea that I may have been sitting on the wrong side of my cr10-v3, as it 'homes' bottom left, rather than top right! "G28 Sweet G28"

I'm sure when I first started using my printer, that the final 'dip' in the homing sequence would stick that snotty bit of PLA to the corner of the bed, before the head moved off to print a 'purge' line. Don't know if that was by design, but must give that corner of the bed a good clean today and see if can do it again.

@Tucats Your Home position will be in one of the corners, and it will always start from there. But where it prints your object on the bed is down to you.

When you download files from Thingiverse and open the .stl file in your slicer, you can then centre it or move it to wherever you want it, before you slice it.

I hope that helps.

@Gil The latest version of Cura is 4.9.1 which you can download from here:-
https://ultimaker.com/software/ultimaker-cura

There is not a special 'machine specific' version.

@Sebastian1982 If you do a general internet search you should find articles like this one which may help: https://superherodiy.com/blogs/knowledge-base/windows-pc-cant-connect-to-3d-printer-over-usb

Its super easy on Linux, but I don't have a Windows pc so can't test anything for you.

Note: 1) although your controller has a USB connector, its really a serial port rather than a proper USB port (i.e. take a look at the controllers About Printer screen and you will see that it has a 115,200 Baud rate.
2) also, do not wiggle the USB connectors. What are you trying to achieve? You will just turn a perfectly good socket into a intermittent one! That "Welcome to Creality" message shows you are forcing the controller to reboot...not good.

@radiantheat Try: M42 I1 P6 S255

Also see: https://marlinfw.org/docs/gcode/M042.html

...and my post on making sounds: http://captainbodgit.blogspot.com/2021/05/my-bleepin-3d-printer.html

Linux users should note that Cura 4.9.0 and 4.9.1 will crash on Linux computers when "Scale" is selected.

The full story, with 3 AppImage solutions, is here: https://github.com/Ultimaker/Cura/issues/9709#issuecomment-844784353

@tognaco Plug the card into a computer and make sure it contains .gcode or .gco files.

Your printer will probably not show files with other file extensions, such as .stl

@Tucats Yes, by tightening the 4 knurled knobs, the bed is pulled down and the springs are compressed.

Initially, tighten all four by roughly the same number of turns so that the nozzle is well clear of the bed (as you don't want the nozzle dragging along the surface of the bed when you check/adjust leveling). Then you can start to re-adjust each corner, but note that adjusting one corner will have an effect on others. So a slowly-slowly approach is required.