Do you pay taxes when selling a house?

Maybe.

If you don't sell it for a profit, there is no federal income tax. (There may be other taxes like local transfer taxes and title fees, etc.)

If you sell it for a profit there may be a taxable gain.

If you owned the house for two of the five years before you sold it and it was your principle residence for two of the five years before you sold it, you don't pay tax on the first $250,000 in profits ("capital gains"). If you file a joint return and your spouse also used the house as a principle residence for two of the five previous years, the first $500,000 in profits is tax-free. If you lived in the house less than two years and moved for a reason beyond your control, you may be eligible for a reduced exclusion. You can use the exclusion no more than once every two years.