The perimeter of a circle is the circumference of the circle.
CIRCUMFERENCE
There are two formulas:
1. C = πd (use if the problem gives you the diameter only)
2. C = 2πr (use if the problem gives you the radius only)
AREA
There are several area formulas for a circle but I think for you at your level of math, A = πr^2 is all you need to know.