I have a 2000 ford taurus and if i’m in gear at a light it makes a loud noise but if i let up on the brake it stops. So what do i do???

If that’s as much as you can say about it then you should drive it to your mechanic or find one of you don’t have one. (Local, independent, with a good reputation). Describe the symptoms and have them drive it.

If you want some speculation from this board, maybe you could start by describing the noise? Including how long its been there and whether or not you’ve done anything - like looked around on the car for something obvious.

If you’re brake rotors are cold and/or wet, and if you are letting off the brake pedal just a little (and not realizing it) the pads will lose contact with the rotors and make a loud sound like crow-barring up an old wood plank. That’s a guess. Next time at stop, look to see if you are moving forward ever so lightly when noise occurs. But
would help to have you describe noise and where you think it is coming from.