I'm betting the bike is good to go as-is. But a lot depends on how the trails are constructed in your neck of the woods, and the weather. In my region, dry rail-trails are almost as smooth, and sometimes smoother, than the roads. Wet trails can be a mud pit if its been raining a lot. I don't do anything special for trails, just ride my regular bikes, including a single speed with 28mm tires and 65 GI. I see every manner of bike on the trails, including skinny tire road bikes.
The fenders might be your friends if it's not bone dry.