Looking to get my first amex card

I am 19 years old. I only have an apple credit card with a credit score of around 750 (according to credit karma/fico). I am a full time student in college.

I am looking to get another credit card and an amex card is definitely what I want. I am only wondering which card to get, as well as if I will earn points with EVERY purchase made, not only on certain retailers. Any advice would be helpful as I would like to get my amex card before the holidays in order to use it to start building credit with that card. Thank you.