Take it to a Honda Civic garage / mechanic.
5w-30
capacity with a new oil filter is 3.8 qts. 1996 Honda civic ex
It should be 3.5 to 4 litres of oil
3.5 guarts
5W-30
M14 x 1.50
3.6 Litres
The dipstick is located behind the steering wheel.
It should tell you on the oil cap you remove to add the oil. My Civic DX uses 5W 30.
SAE 5W-30 is what Honda recommends and that is what you should use conventional or synthetic.
The correct weight which should be 5w20 is listed in your owner's manaul.