Run PSS and Pnoise analysis.
PSS is periodic staedy state. It calculates VCO operating frequency in steady state and Pnoise calculate the phase noise for the defined frequency range.
Yeap run a PSS+Pnoise simulation, you must run the PSS together with Pnoise and set the guessed foundamental frequency of your oscillator, set the harmonic to 7 or higher, set the initial time to 100ns or higher.