you will need a pt (personal transponder) that you buy which has a unique number that the lap counting computer recognizes as you when you book into a meeting and counts your laps,you get these from model shops, the club have some from time to time or you can get used ones now and again,look in the forsale section or try ebay .better with new if you can afford.
a licence
you need what is called a BRCA LICENCE which we can sort out when you come down to race at mmrx
or if you go to the brca web site you will be able to download the forms and do it yourself
hope this helps ,its all stright forward really