As I hope you already know, there is a Spring Election scheduled for April 7th, which includes the Presidential Primary.
You can register to vote at the polls in Wisconsin (with the required documentation), but registering ahead of time will save time, and will enable you to request an absentee ballot.
You can check whether you are registered already, and if not, you can register online at MyVote.wi.gov – DEADLINE Wed., Mar. 18. This is also the date by which a mailed registration form must be postmarked. If you miss this deadline, you can go to the City Clerk’s office to register in person until 5 pm on Apr. 3, with the registration form and required documentation. Use the links to the application form at https://whitewater-wi.gov/170/Voter-Registration, where you also will find information about the documentation required.
Additional information for UW-Whitewater students is available at the Warhawks Vote web page.