This was part of our 1st Degree project as part of a bigger project.
What appears to be missing is the word "Sinusoidal". If this is the case, set the gain to about 4 using the feedback on the -ve input of the op-amp. It will give you a square(ish)wave.
Normally a JFET on the feedback is used to control the critical gain to allow oscillation as a sine wave generator which mathematically is 3. We used a 2N3189
You rectify the output to give a -ve signal on the gate of the FET which forms part of the feedback circuit.
The output level is better set using a second op-amp.
The frequency is set using a dual gang pot which I think you seem to have worked out.
I could dig out a cct if required, but my notes are in the loft and we are talking ~30 years ago.