To join a Blackboard Collaborate session, users must first launch the program using the provided link, then log in with their assigned name. The session is joined once the user's name appears in the participant list. Troubleshooting audio and video issues involves selecting "Tools" and "Audio Setup Wizard" to test speakers and microphones. Users cycle through selecting different speaker and microphone options in the provided lists until they can both hear audio and their microphone is detected.