That's about the same distance I ride with a similar mix of dirt and paved MUP. I have 700x35s or larger tires. Smaller is doable, but not particularly comfortable on the dirt. If it rains, skinny tires are pretty bad on the mud. Get some fenders which will help keep you and your drivetrain cleaner, and get a spare tube, patches, tire levers and a pump and/or CO2. Learn how to fix a flat before you get one.