You got good answers on the oil filter.
But I suspect there were two things you unscrewed: the filter, and the oil drain plug. That plug or bolt also needs to be installed correctly, and some of them have a crush washer, that may or may not need replacement.
And there's a third bolt that often comes out, but obviously you were smart enough not to do this, so you should be okay. But it's not uncommon for a first timer to mistake the transmission plug for the oil drain. No harm done as long as you realize it and put it back in without leaks, and top off the transmission fluid as needed. I have a friend who drains some transmission fluid and some coolant every time he changes oil. He doesn't totally replace either fluid, but he figures over a few oil changes he gets it pretty clean, and he's been driving high mileage cars longer than anybody I know.