Recepticle tester shows reversed polarity. How do I find where the issue is located

I have several outlets out (including one light switch). I decided to buy a Klein outlet tester. I have plugged this into several outlets so far and all read hot/grd reversed on the lcd display. I wanted to test one of the outlets with a multimeter and I accidentaly touched neutral with power (white wire+black wire). The gfci popped (as it should). So i know that gfci is working,after a reset, one outlet after the gfci that was working. the next one was the outlet I tried to test. Does this mean the issue is in that outlet? I have an electrician come in next week, but I like solving puzzles. Anyone have any idea? Let me know if you need more information.