It's got four strings, how hard could it be
I think it's a good idea to rent your first cello. Speaking from personal experience, you could get 3 months into cello lessons, discover some new technique that will improve your bass playing and then the bass guitar ideas start flowing and don't stop for 6 months. It's probably a good idea to return the cello for the 6 months and rent again when you are ready to give it another go.
Many rental outlets will supply rosin, a bow and (mine anyhow) will replace strings in the event of breakage.
Get a teacher, probably in the $40-$50/hour range. Assume 7 hours of practice minimum per lesson and schedule your lessons accordingly.