Spring and summer are better times to apartment shop in Grand Rapids than fall and winter. Come springtime, people who are planning on moving tend to start giving notice, freeing up a greater number of apartments. If you start shopping anytime after April and before September, you should be setting yourself up for success.
Don't let landlords in Grand Rapids make you feel like you have to make a decision on the spot. There are ample vacant apartments here, so don't feel like you have to immediately accept an offer to take an apartment. Shop around and definitely view more than one place before you sign a lease.
Grand Rapids is extremely bike friendly for a Michigan city, with a large network of bike paths. The Rapid is the bus service that operates in Grand Rapids, but the service is fairly limited on weekends. Most people still choose to drive though. A good tip is to park outside of downtown and then walk into the city core, as you'll find more readily available and more affordable parking.
The Frederik Meijer Gardens and Sculpture Park is a large park with many trails, public artwork, and a tropical conservatory. During Wednesdays in the summer, there are free blues concerts at Rosa Parks Circle. Mulligan's is a hip bar frequented by younger people, Billy's Lounge is essentially a blues club, and Founders is a local brewpub that caters to fans of the craft beer movement.