Nice and free websites
3D models to download
A website from BAMBU LAB where 3D printing enthusiasts have posted their designs that you can immediately import into your Bambu Studio to print.
A website by Prusa 3D where 3D printing enthusiasts have posted their designs that you can immediately import into your Prusa Slicer to print.
One of the first major websites with a wide range of 3D models that you can download in STL format and easily import into your slicer.
Draw 3D models yourself?
Draw 3D models by adding and subtracting geometric shapes.
Web application, offered free of charge by AutoDesk, the makers of AutoCADFree and open-source 3D drawing package with an approach like a technical drafter works.
Another free and open-source 3D drawing package with an approach like a technical drafter works.
Draw a 3D model using a scripting language.