Below is the the schematic of an op amp square wave oscillator. Does it look familiar?
simulate this circuit – Schematic created using CircuitLab
That's right, it's your circuit - less the input signal and capacitor.
But how is it an oscillator? R1 is connected from the output to the non-inverting input, providing positive feedback. If the output voltage goes up or down by even a tiny amount the feedback through R1 will cause it to rapidly go further in that direction, until it gets (close to) the supply rail. R2 then charges C2 up or down until the voltage on the inverting input goes past the voltage on the non-inverting input input, causing the output to switch to the opposite rail. This cycle repeats continuously producing a square wave at the output.
To stop the oscillation you can temporarily disconnect R1 and C2, then adjust the potentiometer (represented here by R3 and R4) to 50% to make the non-inverting input 0 V. You should also disconnect the input signal from C1 to stop it from interfering with the DC voltage at the non-inverting input.
After doing this the op amp's output should be close to 0 V. Now add the other components back in (first R1 and C2, then the input signal) and observe the waveforms that occur.
V1
connected while you are adjustingR3
? Please change the waveform image to clearly show the X scale and Y scale. Are you doing this in an actual circuit ? Or just in the simulator ? \$\endgroup\$