Thanks for the question, @CJWhitsett. my.SketchUp stores your models in Trimble Connect, and Trimble Connect allows you to create Folders with read-only permissions as well as invite others to view the folders. You can even group users together and set folder-level permissions based on the groups. To illustrate, I made a couple video resources:
Part I: To create a folder with read-only permissions while using my.SketchUp, check out this video.
Part II: To invite a user to the read-only folder, one option is to create a group for your clients, and always assign that Client group to read-only mode for specific folders. I made a second video demonstrating this process.