That doesn't even come close to providing enough information for someone to even guess what kind of oscillator you need.
What are you going to use it for? What are your requirements (cost, size, accuracy, stability, voltage/power output, adjustability, waveform type, available operating voltage, any special features, etc., etc., etc.)?
I want to generate a sine wave and square wave as well.
Actually I am working on Bio-impedance project and I am making its PCB.
Currently we are providing 15kHz frequency through the function generator but for making PCB, We need to design an oscillator.
We need to provide frequency between 15kHz to 30kHz.
I want to vary frequency smoothly over this range.
And need not to worry about its cost.