3d printers

Anyone know where i can learn to use then? My uni has a bunch of them free to use for students

Youtube is a great resource for tutorials, but a lot of the skills learned are hands on and require you to print something.
One of the best starting builds is the benchy, a stress test and settings tester for 3D printers, Here is the file:
https://www.3dbenchy.com
After You get that down, a good place to look for 3D models is www.thingiverse.com, although their search function is pretty bad.
There are a lot of intresting models people post on there. One of the best models to test your skills is the collapsable katana, requiring a lot of precision to pull off. Model is here:
https://www.thingiverse.com/thing:3639693