We have two kinds of 3D printers:

FDM Printers

"Fused Deposition Modeling"

These are the "classic" 3D printers that most people think of. They can be pretty easy to work with, once you know the basics.

MSLA Printers

"Masked Stereolithography Apparatus"

Commonly referred to as "resin printers", they offer a much higher resolution, but require lots of post-processing and a stricter safety protocol.

Resources

Learn 3D Printing

• https://all3dp.com/

3D Models

• https://thingiverse.com
• https://www.printables.com/
• https://cults3d.com/
• https://www.yeggi.com/
• https://www.tinkercad.com/things
• https://www.stlfinder.com/
• https://3d.nih.gov/
• https://nasa3d.arc.nasa.gov/
• https://3dmag.org/en/market/