How long would it take for me to pass a urine test at either labcorp or quest diagnostics?
Theres no telling. Each persons body is different and there are too many variables to take into consideration. Only a THC test kit (using the first urination of the day) can give you that answer.

Another question, back awhile ago I had I go to court for possesion of weed an paraphernalia. All I had to do was pay my fine and complete community service and it'd be off my record. I wasn't drug tested during this period. Now when I go back to court to show proof of payment and my hours will they drug test me?
Theres no telling. Depends on the juristiction and the judge.