How much time will i need to p a urine test?

i smoked once like in january and then last night was the first time i smoked since. as you can tell, its not really my thing. i was just wondering how much time will i need to get cleansed because im looking for a job right now and i dont want that to hold me back lol. and also im applying at places to become like a bus boy or something simple (im young), do you think theyll even test me?