If you're from California, then you should have a good I idea of places where you can drift. If not then I will list the 2 tracks that I go to all the time to practice drifting. One of the tracks that I know of is in Sonoma, this place is close to the golden gate bridge. Yes, this place is in San Francisco, and the name of the race track is Infineon raceway.
The other race track that I go to as well is in Rosamond, which is close to Mojave desert. The race track is close by the desert and the track is called Willows Spring. These two race tracks are the tracks I go to, to practice drifting. I will give you an overview of how amazing these tracks are and why I recommend them to you.
Let start of with the Willows Spring Circuit, this place is just the places we need when you're trying to practice drifting. There are a lot of run off areas in which you can use just in case you make a mistake. The long straight is about half a mile, which leads to castrol corner where your entry speed will very high. This is essential to gauge your skill by controlling a drift in a fast and precise action. Turn two is the rabbits ear and it's a hairpin, a very long right hander hair pin that is challenging. This corner will test you on how long you can hold the drift. I suggest going in as deep as possible and start your drift mid way through the corner to completely clear the corner.
Turn 3 is a left hander that connects to turn 4 with a right hander, These to corners are a left and a right which makes it a S bend. This corner can test your control of the drift by switching left to right. Turn 5 is a another left hander and then to the morade ridge which is turn 6. From turn 6 all the way to 7 is a slightly bent straight. Try to do some freestyle drifting in the straights so you can see how well you can manage to do it. Then a fast sweeper in turn 8, try going fast before the turn then before the corner; initiate the drift to clear the corner. Turn 9 is another fast corner which lead to the main straight, this is it try your best drift to clear the corner to ensure some praise from the people watching, yay...not.
Overall this place is fantastic and you'll meet a lot of drifters and car enthusiast, some are expert and some who are beginners just like you. This a perfect place to hone your skills and get social with other people who has the same hobby as you.
Finally the Infineon race track is another place where you can hone and perfect your skills in drifting. If you're from the northern California, you should check it out and see for yourself that this place is an amazing race track. This track consist of a lot of challenging corners and a lot of elevation. This circuit is longer and bigger than the Willows Spring so expect to see a lot of people as well. I won't go in much detail in describing this track because experiencing it is much better.
I will try and give you more updates on the race track that I go to so you can try it out yourselves. But these two circuits are the ones, especially the Willows Spring where you'll see a lot of drifters such as yourself. Have fun and good luck to your drifting endeavor.