I found out that the machine I have is a "cookie cutter" machine. The same machine is sold with a lot of different brands on it, so I was able to find a YouTube video with some G-code that solved the problem. I also updated the dimenssions of the machine, even though I measured them myself.
If anyone has the same type of machine as me, even though it's a different brand, you can use this tutorial. After these settings, it printed perfectly.
Thanks though, Greg! It probably was something with the dimensions of the machine. Because the Gcode I used in the video I uploaded here, was the default code.