Thank you for the reply and the details provided above.
I started cycling on a mountain bike when doing munros and then used this on the cycle tracks in Renfrewshire. I then decided to swap this for a road bike and did mostly flat rides to Bishopton and Houston average speed 21km. I've recently joined Strava to try and get my speed and distance up.
The Sunday small ring sounds good, I was just a bit reluctant to join as I did not want to slow anyone down. Upon speaking to Colin he has settled my nerves so thought I would message to hopefully join.