i) That equation looks good. Can you do the algebra and put the numbers into get a value of capacitance?
ii) An inductor or a capacitor can both be considered as having a resistance which changes depending on the frequency of the source. As gneill commented, if you are unfamiliar with either reactance or impedance, this part of the question may be difficult for you.
Also, since the first part was about resonance, can you think of how resonance might help you?