I'd check out Atlassian University as a starting point.
For example, check out...
Or, search for other options!
If you have a team at your company, you could look to enroll them on a course with an instructor? Check out that option on this page.
Or, check out what options might exist for you to join a public course - check that out here: https://university.atlassian.com/student/activity/853037-public-classes-beta