Ican't find the surface area because i have no clue where to find the radius

You are told the circumference of the sphere. The circumference is the length of the circle around the widest part. You know the formula for the circumference of a circle in terms of radius, so you can find the radius of the sphere.

C = 2πr
496.12 yd = 2*3.14*r
(496.12 yd)/(2*3.14) = r = 79 yd

Then the surface area of a sphere is given by ...
A = 4πr^2
A = 4*3.14*(79 yd)²
A = 78,386.96 yd²


You can also find the area of a sphere in terms of its circumference.
A = C²/π
A = (496.12 yd)²/3.14 = 78,386.96 yd² . . . . same as above.

(The surface area in your problem statement, 3117.25 yd², corresponds to a sphere with a circumference of about 98.94 yd. The circumference given in the problem statement is almost 5 times that, which is why the area is almost 5²=25 times the area in your problem statement. This is a good one to ask your teacher about.)