join your loacl motorclub,speak to the members marshal on a few rallies,depending on what you want to do either drive or navigate,check out what class you want or can afford to be in,check out the competition and apply for a licence from the RAC buy or build a car spend the next year in finanical ruin and in the garage repairing it
but it fun I had 10 years at it ended up the top of the tree in my class