Dude,
Something to think about......
You need a trailer and something to tow it with. I have known people to rent a UHaul to get to and fro the track. $$$
Gas, insurance, taxes, maint, any repairs to to towing setup. More $$$$
Some tracks have weekly entrance fees, or yearly membership fees/lisences. Usually tires and gas have to be bought at the track. You can run one tire at track A, then decide to run track B next weekend. Guess what.... you can't use the tires you just bought last weekend at track A. If you wanna run, you have to get a set of tires from track B. More $$$$
Race cars break parts period.... Even the little 4 cyls break stuff all the time. Clutches, shafts, bearings, internal engine parts (it's common for 4 cyls to run +7k rpms), rear ends...... You will have a fender bender or 2 here and there.... You will need a welder/skill of welding and occasionally some tubing... More $$$
A big part of running up front is your engine. I'm sure you will want to run up front, and you'll start spending $ on high performance parts. You can easlily nickel and dime yourself to death trying to find 15 hp. Having a performance engine built.... I've heard as much as $8k for a 4 cyl and $25k is common for a Modified/Late model...... That high performance engine... breaks other stuff down the drive line....Real $$$
If you enjoy it you will want to start tinkering with stuff....
Trying new springs, shocks, cams, rear ends, fluids, pulleys, timing, suspension adjustments, ect, ect...... it adds up to more $$$$ and a ton of time......
You will need a fire suit, helmet, gloves, and shoes. None of these are anything to skimp out of. More $$$$$
If you really still want to do it.... Find a sponsor, period. Once you get your requirements (suit/helmet/car/tow rig), it is possible (with a sponsor) to run some classes with little or nothing out of pocket as long as you don't tear up a lot of stuff. It's really helpful if you know someone who competes regularly. They can help you learn the tricks of the trade (how to cheat, characteristics of the track). Once you're in make every friend you can but keep in mind people will lie to you... (most don't give away thier secrets).It is a lot of fun and You'll meet some really great people, but if it is a motorsport it's really an expensive hobby.