Hoping not to be offensive, reading your question I think you are not familiar with electronics. An LM324 cannot accept 230Vac between its + and - input terminals.
If galvanic isolation is not of importance, a resistive voltage divider is used in most cases. However a general-purpose resistor cannot handle 220V safely. This means you need special resistors, or you need to use several resistors in series to share the voltage so that each resistor experiences a relatively low voltage. Note that the mains voltage also has transients into the kV range that damage your equipment.
If you only want to measure the 220V mains, you may use a non-encapsulated mains transformer and use the low voltage secondary as the output that goes to your oscilloscope project. You may wind your own secondary. Note that the peak voltage of 220V mains is around 310V.
Think twice (or more) before connecting some home brew circuit to the mains.