I need help

Rise doesn't include that sort of pop-up functionality. 

Yes, you can insert glossary terms in your course. Where and how you do that depends on the number of terms, the design of the course, etc.  

For example, if the navigation is locked, you could put the glossary in the first lesson, so it would be accessible right away, and users could always go back to it. Or you could start each lesson with a "Here are the terms you need to know..." section that defines the new terms in that lesson. 

If you have a lot of terms, consider putting them in Storyline, and then inserting that as a Storyline block. There are many examples in the Forum of glossaries. (Here's one I did years ago: https://community.articulate.com/discussions/building-better-courses/free-download-custom-glossary-slide-40a10aba-cb7c-4076-8fcb-757843155cec )