Where d’ya ride?
If it’s hills “n” stuff then the pace will be a lot slower as the climbs get harder so only use the above as a very rough guide.
Down here in the South Downs the pace for the “novices” (incl newbies, women (no not all women before you lot start) kiddos, veterans, cake afficianardos (they stop twice during the ride) ave 14mph, the fast lot split themselves into two groups.. The fast lot 1 ride out hard and contain ex pro’s and moi, ride out takes about 3-4hours at ave’s of 20mph+, the fast lot 2 tend to go on shorter routes (1-1.5hrs) and ride harder on loops and ave about 25mph+ (contains TT fellas and blokes who want to get home early)
Very rare you’ll be dropped, most riders will keep an eye on you but if you can ride no quicker than say ave’s of 18mph then join in on the slower group and pace yourself until you feel you can join in on the fast group(s)