QDM
To add to John`s tips;
You must fly dual with someone who knows (pref ex-mil, but there a lot of excellent civ. formation instructors).
Don`t just read about it and then go fly.
Don`t fly dissimilar a/c in formation until you have a lot of experience.
If you are inexperienced and still ignore all b4, only go as a pair.
There were threads about formation schools/courses some time ago, so a search will show them.Y ou can learn basic formation in a few short hours,given the proper training and it is good fun,teaches you a lot about airmanship,and aircraft control,
as I`m sure lots of Ppruners who have done the course at Nweald would endorse- just be careful.