Two is standard. Some people are only born with one, or have one functional one and one defective one. Some people have 3 (unusual).
You only have 1 liver, 1 spleen, 1 pancreas, 1 bladder, 1 heart as standard.
2 kidneys, 2 gonads (whichever flavour), 2 of each limb, 2 lungs as standard.