Continuing the discussion from Welcome to our forums! Please introduce yourself :
SketchUp models certainly can be 3D printed.
The model just needs to be a watertight closed volume called a SketchUp Solid.
Here’s more about what makes a model suitable for 3D printing:
Understanding Solid Objects in SketchUp — Aidan Chopra
These Solid Modeling Inspection/Repair Tools help you find hard to spot solid modeling errors.
ThomThom: Solid Inspector²