The WSU Vancouver Campus has a lot of interconnecting trails. It's best to take a look at the official trail map as there are a lot of trails that aren't documented here. There are several loops that provide a nice casual ride around the campus.
The jogging trails are hard-packed singletracks and you'll want to explore those to see what direction to take them. Several of these trails are too steep to ride up, and are black diamond due to the steepness of the trails.
If you stay in the open areas, and avoid the jogging trails, you'll have a nice and easy ride around the campus on bark covered doubletrack trails, hard-packed doubletracks, and some paved segments.
If you want to extend the ride you can head down to the south entrance on NE Salmon Creek Avenue and follow it over to the Pleasant Valley to WSU Connector
If you head to the west side of the campus, between the parking lot and basketball court, there is a short dirt connector to NE 29th Ave. Make a run over to NE 144th St/NE 20th Ave/NE Union Road/NE 15th Ave/NE 179th St/NE 10th Ave. You'll be over at Fairgrounds Park Path
and can make a run over to Whipple Creek Way