The Bicycle Repair Shop does rentals by the hour or by the day. They have reasonable rates. They have solid, lightweight hybrid bikes so you can tackle train tracks and brick streets and hills. They also have road bikes for the more experienced. You can reserve online in advance. You get a helmet and a lock with your rental. The staff in the shop are friendly and will suggest routes and point out hills if you're new to the area. And believe me these hills are no joke!
Be organized. “I like having everything be really small and super organized. I put all of my tools in CamelBak’s Tool Roll. It’s got little compartments, and I can separate tire changing stuff in one place, stuff like extra pedal cleats or an extra derailleur hanger in another, and it all rolls up into this tidy pouch. If I do have a repair, I can pull that one thing out and lay it out on the ground and it’s easy to work.”