First off, Congratulations to Geraint Thomas for winning Le Tour de France. He's the first Welshman to do so, though I think they should be called cetaceans (science joke).
It's the ultimate group ride. How do you feel about those?
There are plenty of things in the endurance world that are nerve-racking, intimidating, confusing, etc., but one aspect that should not be is riding with others.
It took me months to build up enough courage to do a group ride when I first started. I fell over at stop lights, did not know when to brake, and assumed (being a college football player) that I should always be in my hardest gear. Therefore I made the dumb decision that riding with a group was out of the question. Those first six or so months of riding were the worst of my life. All the questions I had, and some I did not even know I should have had (such as not wearing underwear under my bibs, which was less than comfortable), were answered riding with other people.
There is absolutely no reason to not ride with others as a beginner. There are a plethora of reason to not want to ride with a group: “I don’t know how to brake right;" “I’m worried about people riding the close to me;" or “I'm going to slow everyone down." These are all bunk. The fact is most, if not all, experienced riders are not going to let a beginner crash or want to ride all that fast. A group of seasoned riders are going teach and show a beginner the safest way to ride in a group, because no one wants to ride with a squirrelly rider.
As crazy as it sounds, it is beneficial for an experienced rider to ride with beginners every once in a while. There are few better ways to truly understand a subject than to teach it to someone else. Beginners riding with experienced riders is mutually beneficial.
There are some important things for all cyclists in the group to keep in mind when riding together.
The most important is BE HONEST and let the group know you are new. This way everyone knows and everyone will be more open and likely to give tips and pointers.
Do not ride beyond your limits. If you are concerned about corners, drop back when a turn comes up. At least the first time out, ride with the “B” group. You can never be quite sure how fast or aggressive the fast group is going to be, so ride with the older cyclists that are going to tell some stories and give a few more tips.
Do not try new things on the first group ride. If you have never pulled a bottle out a cage during a ride, do not do it during the group ride. If you have never eaten on the bike, do not try eating. Definitely do not try clipless pedals for the first time at your first group ride.
Be willing to learn!
Be nice! You were brand new at this some point. Cycling has brought a great deal of joy to my life, and I can think of no better way to show my appreciation than to help others enjoy cycling.
Watch others. I have identified and fixed more issues with my own form through seeing it in others.
Never assume anyone else knows how to ride in a group. Some of the worst crashes I have ever seen have been caused by an experienced rider assuming the rider next to them knew how to ride in a group. Case in point: cornering in a double pace line. A new rider, and even some seasoned riders, can get spooked by riding inside on in a tight corner.
Remember, group rides are a great way to log those base miles. Never be afraid to ride with others, it a great way to learn something, experience some new roads, and make some riding buddies.