Have you asked your doctor to explain these things? He/she should be making sure you understand.
What was your PSA prior to surgery? Was your surgery to remove your prostate? Remove cancer?
Generally speaking, the lower the number, the better, but it's important to take into account any increases.
https://www.cancer.gov/types/prostate/psa-fact-sheet#what-is-a-normal-psa-test-result