Of course angular frequency =(2)(pi)(frequency), always.
The second part, 1/square root (LC) depends what you mean.
The resonance frequency is a property of the circuit, irrespective of whether there is any signal going through the circuit. A passive circuit cannot change the frequency of the input signal, but it can change its amplitude. The frequency in the passive circuit will always be the input frequency, the resonance frequency is irrelevant.
(Of course if the input has many frequencies, the passive circuit can attenuate some of them while mostly passing just the ones close to its resonant frequency. )