Can you describe more about the issue you are having?
If your leads are signing up on your marketo form, they will become members of the Program.
What is their member status? Is it "Registered" from the Change Progression Status flow step? If you've missed this, then NO leads will sync to GTW.
If your GTW password changed, then you need to go back and re-enter the correct user info in Admin > Event Partners.
Kate's correct that you may need to start over. Before you do so, verify the sync is working by registering a test lead and refreshing the Program Members list. Then watch the GTW site for the registration. If it worked, then you can select the other members who did NOT sync, then highlight them and say "Change Progression Status to Registered" and they should sync to GTW.