Hey Nancy Hirdt,
Thanks for the question, and welcome to Apple Support Communities.
Let's check to make sure that everything is configured correctly to sync music to your iPod. The following article will provide help with that:
Make sure that the "Sync Music" checkbox is checked, and that we are syncing the entire music library. If we are not syncing the entire library, make sure that the newly purchased items are included on a selected playlist or genre (you could also check the "Purchased" playlist). Here is a visual demonstration that may be helpful: