I just took my first Ap this year and the general consensus from my friends and the internet is that I had the hardest exam form and that the other 2 were relatively easy. Will my scores be compared to the people with the same form as me or all the forms? I took Ap euro btw if anyone was wondering.
It doesn’t matter what form you take; they’re all scored independently, so it takes into account the differences between forms. They’re actually not score on a bell curve; instead, the tests are (supposedly) given to college students taking an equivalent course and the cuttoff for a 5/4/3/2/1 is based on the scores earned by college students who received an A/B/C/D/F in the class. That’s why different tests have different pass rates – if you need a 50% to get a 5 in AP Calculus and 25% of students do, they all get 5’s automatically, you don’t have to compete against the other students (although I’m sure they take that into account somehow, it’s not forced).
You’ll be fine! You’ll know your score in less than a week anyway. Good luck 
Yes, every test is scored independently and against a set of criteria that measures how well you have mastered the material.
If everyone taking a test shows mastery of the material, fully equivalent of having earned an A+ on the college-level material, they would all get 5s. If no one showed any knowledge, they would all get 1’s. They are not supposed to be comparative tests, like the SAT.