There are lots of ways to get involved in motorsports from helping a friend with their car, being a corner worker or even racing wheel to wheel. Most people I know have started with an interest in either cars, going racing or just being introduced by a friend who was involved. Here are just a few ways you can get involved if you are interested.
How to get involved in motorsport:
1) Attend an event
Whether it is a high profile event like Formula 1, NASCAR or your local club race you can attend and enjoy the thrill of motorsports. Attending events that you are interested in provides a lot of opportunities for you to see the various roles from volunteer workers to the racers. Local club events provide easier access and more opportunities to see the culture, interact with the people, ask questions and learn more details about the various roles. The racing calendar for the local track and clubs can be found on their websites. Here is the SCCA San Francisco Region. Most local club events are free or have a cheap gate entry fee (~$10-20) and just require you to sign a standard racetrack waiver when you enter the facility. You can walk around the paddock and also spectate the track to watch some of the racing action.
2) Join your local club (SCCA, NASA, SVRA, VARA, VSCCA, BMWCCA, PCA, ETC)
If you decide you like the club and want to get involved the first thing to do is join the club. You can join SCCA here. Depending on the club this normally involves an annual membership fee that runs ~$100. Membership allows you to get involved with the club, a newsletter or magazine and even access to member discounts.
If you know what interests you or where you want to volunteer, contact the local representative. Their details are normally listed on the club website or can be found by calling/emailing the general contact for the club. If you don't know what you want to do, contact your club and see what they need help with or where you can get involved. Volunteers are always greatly appreciated and an essential part of motorsports. You can fin more information about Volunteering with SCCA San Francisco here.
How to go racing:
If you really want to go racing there are lots of different types, including: autocross, time trials, karting, or wheel to wheel road racing. Outlined below are the steps to become a racer for wheel to wheel road racing.
1) Join SCCA, NASA or your local club (SVRA, VARA, VSCCA, BMWCCA, PCA)
The first step is to join a wheel to wheel road racing club, normally an annual membership runs ~$100. Membership allows you to get involved with the club, attend member events, a newsletter or magazine and even access to member discounts.
2) RENT, Buy, Build or Borrow A RACE CAR
Before you can go racing you are going to need a race car. There are four options either rent, buy, build or borrow each has their advantages. Building a car will allow you to learn a lot about the car and tailor it to your needs but it can be very expensive and if you don't know all the ins and outs of the rules you might make modifications that are not allowed. It is in general cheaper to buy a car that has already been raced then it is to build one. A used car with a log book will likely be compliant with rules however, there might be some maintenance needed and idiosyncrasies from the previous owner. When buying a car you can find out a lot about what to look for/avoid by visiting the forums, talking to the local racers, or visiting a local preparation shop specializing in that type of car. I would recommend that you rent a car first, it allows you to decide if you like that type of car before you purchase and also provides you trackside support so you can focus on the driving and not feel rushed dealing with all the trackside needs especially on your first few weekends. If you are really lucky you might be able to borrow a race car from a friend and just pay for some of the operating expenses.
3) Safety Gear
Next you are going to need some safety gear including a helmet, race suit, gloves, shoes, socks, underwear and likely a head and neck restraint. You can either purchase new or used gear or even borrow some gear from a friend to try before you buy.
4) Get you competition license
Next, before you can start racing you need to get a competition license. Much like getting your driver license for the street you need to go through some basic training and put it into practice. There are a couple of ways to do this 1) attend a professional racing school (Skip Barber, Allen Berg, Bondurant, etc) or 2) most clubs have a drivers school before the racing season starts, late February or early March. Both of these methods involve a series of classroom and on track sessions to practice various skills such as the racing line, track awareness, practice starts, passing and driving at various speed levels. After this you will likely get a provisional license that can become a full license after attending several races depending on the club. Keep in mind the car you use for drivers school doesn't have to be the car you take racing but it does have to be race car outfitted with all the necessary safety equipment.
5) Buying a race car
Now that you have your license it is time to decide what car you want to race. You can continue to rent or consider purchasing a car. One thing suggested to me was to rent a variety of race cars to try them out in your first few race weekends and make sure you like the car before purchasing one. A used car with a log book will likely be compliant with the rules however there might be some maintenance needed and customization from the previous owner. You can find out a lot about what to look for/avoid by visiting the forums, talking to the local racers, or visiting a local preparation shop specializing in that type of car. Most used race cars in the region are known to others. Cars normally go on sale because they are 1) upgrading to another car, 2) switching class, or 3) getting out of racing. Ask around most people are very friendly and happy to provide advice. Sometimes there are even buyers guides on dedicated forums like specracer.com, apexspeed.com ,etc.