am 23.is it late for me to start rock climbing???

no. anyone can do wall climbing at any age.
if you're talking about competitive climbing, maybe you are too late for it since climbing involves experience especially developing muscle memory for automatice balance and movement. But do not give up, if you are really into it, work hard.real hard. Train and practice as often as possible. If you are not able to enter any competition, at least you have learned a great sport.

no l did not start until l was 26

l started when l was 25. You can start at any age.