I think you've made a smart decision. We bought a used Sprinter B five years ago, Took it on trips lasting weeks or months, and loved it.
Many class B RVs are designed inside much like a boat, with cabinetry fitted into curves and crannies to maximize use of space. B owners figure out how to put items used daily in the easy-access cupboards. You'll find all kinds of handy items like the Pico camp chairs that fold to the size of a laptop.
After DH had hip replacement surgery December 29 one year, we were on the road in the B again by early February. The surgeon signed off on it (with short days and regular stops) because a B is not much different than driving an SUV.
Enjoy it!