I started racing at age 54 doing two local "citizen races", which I was woefully unprepared for. I got the bug to continue racing and decided to begin training and preparing for racing by doing things off the bike like loosing weight, working on the core muscles and making decisions in daily life that would enable me to ride more and faster. Over the past two seasons I really enjoyed the competition of racing while the improvements to my riding were a secondary benefit which is very nice.

I say do the race. Your friend must see something in your riding that he would suggest racing. It may be an eye opener due to others who have been preparing for racing for an extended time and seem out of your league. Keep an open mind that you are new to racing and don't expect to be invited to the TDF right after the race. You do have time to do some interval training to get you body ready for the change of pace in races. If you like the competition and want more, then you can begin training for more races, then who know where you will end up.