Hi Lauren, here's what I suggest if you'd like to keep it simple with a single task.
Ensure you have job roles defined for "Student" and "Staff"
Add those job roles to the user profiles
Assign a task for the training with Duration Type=Simple
Assign users, roles and hours to the task as seen here:
Train users on clicking "Done With My Part" so the task remains open until both have completed their part
Thanks, Narayan