Two of the keys to getting faster is practice and concentration. You have to know the car and the track well in order to be the fastest you are going to get. If you don't have a lot of time to devote to practice then you will be ok, but there will always be people that can turn laps 1 to 2 seconds faster than you. Concentration is a huge factor and can make or break your race every time. If the dog barks, or the kids are bothering you for supper, you are not going to do as well as you could if you were alone and totally concentrating on your racing.
If this is just a casual thing, then obviously you are not going to be able nor want to devote the time needed to be one of the fastest on the track. Over time, anywhere from a few months to several years you might become one of the fastest but in the short term you will be a mid to back marker when the fast guys are on track. This is not a bad place to be btw. If you enter races with the faster drivers, you get to see how consistent they are and how they handle corners and passes. They get to be your teachers just by racing with them.
If you have your system setup to record races, you can review the races later on and see where the fast guys start braking and where they start turning in so you can strive to duplicate their driving technique. I do have to warn you though, that the fast guys are almost exclusively running setups adjusted to their driving style and the track they are on. If you are not familiar with how to create setups that work there are a couple of threads on the concept. If you can't make heads or tails, give me a pm and I will help you understand it. Just remember if your lap times are not within .5 seconds of each other or less, changing the setup won't do you much good as you won't notice it's help. This is of course presuming that the setup you are running is not way off to start with.