resistivity is a property of the material, resistance occurs in a circuit- I'm assuming you'll probably be giving an ammeter and a voltmeter, as well as different lengths of wire- you'll probably just have to set up a series circuit- with a length of wire inserted as a component- you should include the ammeter in this, put the voltmeter in parallel to the wire. Record the voltage and current and use the equation v=ir in the format r=v/i to work out resistance- seen as there isn't a resistor in the circuit, the resistance must come from the wire and is actually resistivity. Then you'll most likely draw a graph and have to explain what you see on it (eg. the pattern etc.) if it's a qualatitive paper it will be about how you do the experiment, if it's quantative concentrate on the maths and the units and if it's evaluative- look for the problems in the way the experiment was carried out.
good luck