With your GPA you have a good chance at scholarships, so I would apply by the priority deadline. That being said, almost everyone applies to meet priority deadlines, so you'll want to submit about 4 weeks in advance of those deadlines to account for the massive backlog that my occur during the verification process. Many schools will not look at your app until it is verified, so plan accordingly. See if you can submit pending GRE.
Four weeks prior to your first deadline. Figure out which schools are due first, select those designations, and submit. You can add new designations after your app is verified. Verification happens only once.