If there was an easy answer to this question then everyone would be amazing
All I can tell you is to practice. Go out onto the track and find the fastest line then follow it lap after lap and become consistent. If you can hit the same line lap after lap without wrecking then the speed will come with time. I always like to set goals for a certain race that are reasonable, but at the same time challenging to obtain. If you push yourself a little more each week, you will become faster every weekend.