can someone please help me in how to go about solving this problem?

problem: A particle moves in a straight line and has acceleration 6cm/second square.Its initial speed is -2cm/second. Its initial position is given by f(0) = 9cm.

Find the position function f(x), where the input means the time.

here's what i know:

acceleration is f"(x) and speed is f'(x).

so i assume im looking for f(x).

but how do i setup the equation?

thanks!