"Your part" is whatever you want it to be. Perhaps you are ready to join a project? Just go to the top of the page and look under the "Find" menu item and click on Projects. Some projects have more direction for what needs to be done. Data Doctors is pretty good because you can pick up tips on a better way to care for your own profiles.
If you don't want a Project per se, use the first menu item at the top of the page, "My WikiTree." These all relate t whatever you have entered. You can find suggestions for your profiles that you can work on.