Bit of a long post as the club caters for pootlers right through to virtually elite riders but I will try and give you a good overview based on my own experience.
Officially there are 2 groups the 9am group who do 40-50 miles at 16-18 mph and head out to the hanningfields and a 10 am group who will do the same speed but over a shorter distance say 25 miles both start and finish at the village hall. There is parking or you can add riding to and from distances to that total
What actually happens in practise is you will get the 9 am group going out and splitting into two groups 1 riding at around 16-18mph avg and the other can get up to 22-24 avg both then re group on the way back and then all hell breaks loose but only for those that want to, so this one can get pacy on the way back (Coventry Hill in Hullbridge is normally the point all the way back along Lower Rd to Canewdon), although there is always a group who continue to go steady. If you are new to group riding and cannot hold say a 16-17 average on your own for say 25-30 miles I would avoid this one as it does have a more training bias. Having said that they do wait and you will not get dropped.
On the 10 am group you start as one group and do training laps based around Canewdon. These start steady but do tend to build in speed after each lap (each lap passes the village hall and when the pace goes up the lap size goes down so you are never more than say 3 miles from the hall should you go pop). What tends to happen is as the speed builds the group will naturally splinter but there are always loads of old hands on the rides as all have differing abilities so you will probably have a few members in each splinter group to ride with. If the group deviates from the typical training route then it is steadier and no one gets dropped the group will reform at junctions etc. This is really a cutting your teeth group getting you used to riding a faster pace and they will practise group riding etiquette so do not be surprised if you end up practising a team time trial one day
There is also a 10am social group who start steady and stay steady throughout the ride 13 mph average around 20-25 miles. I think this may be a bit too genteel for you.
They have also introduced a once a month intermediate ride around 20-25 miles this depending who turns up can get split 3 ways, you have a fast, medium and a slower intermediate group. These tend not to start at Canewdon and go from Battlesbridge or South Hanningfield. Each group follows the same route and has a ride leader and tail ender so if you start and the pace is too quick you can hang back and wait for the next group but do tell the ride leader as there is a strict no drop policy.
In terms of distance you will have no real problems on that score and in terms of speed you would probably be OK for most of the ride, as you do not have to do a pull on the front if you don’t want to.
I probably should be in the 9am group however if you do fancy it let me know and I will make sure I’m in the 10am that day.