Hi @Natalie Beiler - we're so happy to have you here! I think to start, a good group for you to join would be the Research & Healthcare industry group, and also possibly the Confluence, Jira & Opsgenie product groups, since those are what you've been working with.
Depending on your role at your company with these Atlassian products, there might be other groups that would be a good fit for you, too (for example, Jira Cloud Admins or the Teamwork Lab).
In terms of learning about our community, I recommend you check out this page which takes you through lots of different resources to help get you started.
Thanks for introducing yourself and welcome!