Good example is turning left on a red light. Everywhere you have to come to a stop first. But then you can turn left on a red from a 2-way road onto a 1-way road in Alaska, Washington, Oregon, Idaho and Michigan . In many other US states you can only turn left on a red light if you're already on a one-way road and turning into a 1-way street. Other states you can't turn left on a red light in any circumstances.
Sample questions for getting a learner's permit online for 2 states:
There are lots and lots of online companies who will for a relatively small fee ($50 or so) give you example tests, with answers and study guides, specific to whichever state you need 'em for.