As for the cycle, many will speak against the fish in cycle. I have used it many times, but on larger tanks with 1-2 fish max. I also have water ready for changes at all times so if the ammonia starts to climb I can do water changes.
As for a clean up fish for a start, this can be a little tricky. About the best clean up fish, I like the lawnmower blenny, but not so sure it should be the first fish in a fresh tank. If doing a fish in cycle, I use aquavitro seed, and dose the recommended amount daily, along with prime to neutralize the ammonia. Our smallest tank is a 75 with sump, so about double your volume. The smaller the tank the higher your ammonia will be.
The suggestion of a clownfish I would avoid. They are a truly hardy fish, but they can be terribly territorial, so may make later additions more challenging.