I don’t imagine you want to ride everything at your limit, so these would be a good mix of social rides (events) to try…
- Any PACK 1.5 Beginners Ride (I like Saturday morning which is “Coffee with Karen” and normally around 45 minutes)
- The HERD Down Under (on Wednesday morning for an hour)
- DBR Social Ride (on Sunday morning for an hour, and could be more challenging depending on the route chosen)
All those have friendly people who’ll help with any questions and also drop back to support you if you’re struggling with the pace (you do need to stay with the draft to have a comfortable ride).
I would say, not all group D rides are equal. If you do want a challenge for your current level, you could try the W/KG 2for1 Down Under on a Thursday morning, which would be at your limit.
Personally, I like to mix social rides with some (but not much) structured training. I did do the 6 week FTP programme, but did it alongside the Tour For All so there might have been an element of over training. There is a Build Me Up plan which might be of interest to you if you wanted to be quite structured (then it becomes a balance of how much group riding you want to do).