You should always verify that the work is actually under a CC license when conducting a search on any website. If you are in doubt you should contact the copyright holder directly, or try to contact the site where you found the content.
For information on how to use the library's Innovation Lab and Makerspace to 3D print, visit the SNHU Innovation Lab & Makerspace website. For a comprehensive list of websites, see Where to Find 3D Models.