How to calculate the collector resistor of this emitter circuit?
Based on the numbers you have, and assuming you want the collector to rest at 50% of the supply voltage. then Ohm's Law:

E = I x R

R = E / I

R2 = (Supply/2) / 0.005 A

R2 = 5 / .005

R2 = 1 K

Note that the circuit will not actually work.  Biasing the base with a single resistor is called dangle biasing, and is severely unstable.  The gain of the transistor changes with temperature, with changes in collector current, and from part to part.