You haven't mentioned what lens you're using, which can make a difference. If you're using an EF or RF lens, then your camera should be delivering full resolution -- your pictures should be 6000 x 4000 pixels, and printing should not be an issue.
But if your lens is EF-S or RF-S, then the camera will go into crop mode (it has to, because those lenses only cover a smaller part of your sensor), and your images will be more like 3744 x 2496 pixels. This would obviously make the files smaller. You should still be able to get decent prints, but not as good.
Other than that, as others have pointed out, the file size in MB is not critical; and if you're concerned about getting the best quality, shoot in RAW. RAW gives you more bits per pixel, which can matter more than the number of pixels.
BTW when you say "I wanted to print up one of the pictures in a bigger size, but there wasn’t enough MBs to allow it" -- it does sound like you're confusing MB, megabytes, or file size -- with pixels. Those are different, though not completely unrelated, things.
If you want to know more about lens compatibility, I wrote an article about it: https://moonblink.info/MudLake/gear/lenses
