Learn the Basics (Basically for Free)
Now that you have all the gear we need, we can start learning the mechanics of speed. Before you jump into your first official race, its best to hop into a testing session and focus on learning how to handle the controls, the racing line, and car control. The above video provides some of the best free instruction available to a beginner driver looking to learn the basics and improve their technique.
Once you have finished watching, hop into a test session on iRacing or whatever racing game you have access to and try to apply the concepts. You will be looking for consistency. A good exercise is to run ten laps and attempt to make every lap within 1% of your fastest lap. (If a 1:40.00 is your fastest lap, all laps should be no slower than a 1:41.00 lap time)
When you can cut ten laps with a consistent pace, you are ready to race. Find a race featuring the car and track that you have practiced and join. The goal of your first race is to finish unscathed and to minimize mistakes. You may be far off pace, you may be on pace. If the latter is the case, try to gain position or maintain your position in the field. The ultimate value of your first races come in the review.
It is absolutely critical that you review your races if you want to gain speed quickly. You should review the racing lines of the fastest drivers and compare them to your own. Observe where they brake and return to throttle relative to your own braking points. Additionally, you should observe any significant moments of your race. Did you spin or go off? If so, try to reconstruct what lead to that incident and explore what you can do to avoid those moments in the future. Also observe any moment that you were overtaken or that you were able to overtake an opponent. What lead to those passes? Was there anything you could have done differently to avoid being passed? Did a pass you executed lead to you being overtaken again on the following straight?
If you review each sim race with this same level of scrutiny, you will become a considerably more aware and effective driver. The knowledge gained here will allow you to adapt and improve at a much greater rate when you finally roll out onto a race track for the first time.