I have been very lucky over the years to get race entries and parts paid for by sponsors. However you can be a brilliant driver and not get a penny if you don't know the right people. Unless someone you know has a money tree in their garden, to get a sponsor in this economic climate is just about impossible especially actual money (possibly oil etc).
I hope whatever you do in the end you will enjoy it as it is addictive, if you do choose to buy a car get one already prepared and something that is easy and cheap to work on ! Go on you know you want to