Thats what Im worried about when i go to get an alignment. My car is set up just the way i like it at the moment(im scared to change it

) but it does handle very nicely. I almost NEVER encounter under OR oversteer(maybe a lil) on the street, which is perfect. On the track however I get alot of understeer which is probably nomal b/c im still a rookie driver and I think my instructor was a lil too used to his RWD, but I didnt want to go against what my instructor had to say.
BUT ANYWAYS.....I basically just want to get my car to drive straight(toe) but dont know what the toe should be set at for my racing purposes. And I still have no clue what caster is, i still need to research that. any help?btw its a honda civic hatch(EK).