The next election is the big one, the Presidential Election, held every four years. While voting would normally take place largely on November 3rd, recent changes to Michigan election laws, and the Corona virus, mean that voting in Saint Clair County will start September 24. Eligible voters (pretty much everyone) have several options. Voting by mail ballot may be done either by having requested a ballot when the state sent out mail asking if you wanted one, or by going to the Michigan Voter Information Center at: https://vote.michigan.gov/AVApplication
Voters may vote in Michigan at their local clerk's office before election day by filling out an absentee ballot application, turning it in at the clerk's office, then filling out your ballot there and turning it in to your clerk.
To register to vote in Michigan, either fill out and send an application, online or postmarked to your clerk's office by October 19. Or you can register at your clerk's office as late as 8:00 pm on election day! You will be asked to provide proof of residency and proof of eligibility, meaning you are: a United States Citizen, a resident of the appropriate jurisdiction, at least 18 years old, and not currently serving a prison sentence.
The above information is taken from the Michigan Voter Information Center webpages starting at: https://vote.michigan.gov.