What is the magnitude of the orbital velocity in ms of

Question

Solve the given questions:

Question I: What is the magnitude of the orbital velocity, in m/s, of Mercury around the sun? The orbit radius of the Mercury is 5.79 x 1010 m, the orbit period of Mercury is 88.0 d.

(m/s)

Question II: What is the radial acceleration, in m/s², of Mercury toward the sun?

(m/s²)

I known the correct answer but I need to know how to get that. Thanks!