Those symptoms indicate that you likely lost your serpentine belt. The belt itself is not an expensive item at all but there is usually an underlying reason for it coming off.
You need to inspect each one of the pulleys and spin it by hand to see that it riolls smoothly. Visually look at the pulleys to see that they align with each other and none of them are leaning or anything.
Let me know what engine it has and I will give you a diagram of the belt routing.
The spring loaded tensioner is #8 in the picture and you rotate it clockwise to relieve tension.