I would do core exercises to keep your body strong to make up for any weakness in the neck. I would work up to riding whatever you can ride, with no hard and fast rules. If you have pain, I would see a PT.
My only expertise is anecdotal; I have a bad neck but with physical therapy and keeping up with core strengthening exercises I can now ride all day.
Trek Madone 4.7 WSD
Cannondale Quick4
1969 Schwinn Collegiate, original owner
Terry Classic
Richard Feynman: “The first principle is that you must not fool yourself and you are the easiest person to fool.”