Do you know the definition of a derative? If not this is it

as h approaches 0 (didnt know the latex for it)

simply plug in x+h for the input for your f(x) function in the part that has (f(x)+h) and simply same with the next which is just the function you were given, now simplify and take/find the limit as it approaches 0 and repeat the process again to get the second derivative

for the first derivative's setup youll have something like