Find the exact value of: sin60-cos60.

do I just type sin60-cos60 in my calculator?

= .37

no

if it says to find "exact" values, don't touch your calculator.
In this case you would be expected to know the ratio of sides of the standard 30,60,90 right-angled triangle

the sides across the angles 30,60,90 are
1,√3, and 2 in that order.

so sin 60 = √3/2 and cos 60 = 1/2

so sin60 - cos60 = √3/2 - 1/2
= (√3-1)/2

(of course it would be a good idea to test that answer on a calculator, it works!)