In order to be eligible to vote in an election other than the Presidential election in November you must be registered to vote 30 days prior to the specific election you wish to vote.
You can stop in to City Hall and the City Clerk's Office will be glad to assist you with the necessary paperwork.
Or...
To register to vote or update your voter registration record, you (or an individual with a general power of attorney or special power of attorney authorizing that individual to register you) must complete and sign a Voter Registration Application.