TTs are a great part of training at threshold and above. It is you against the clock (you can also ride in a pair or team). The club TTs cover various distances at quiet times in the evening, with the courses signed and marshalled. The process is as follows:
1.Find a bike (any roadworthy bike will do with lights)
2.Turn up 30 minutes before start to sign on
3.Ride as hard as you can over the given distance
4.Repeat from 1 to improve your time or do it just to keep fit
A full list of dates and routes are provided here https://nnwheelers.co.uk/time-trials/
Give it a try, we are all friendly!