Ok, so if the train stops at terminal A , but you need to go to another terminal, how do you do so?

Depends if you have to check bags you'll need to take the terminal shuttles if you're only taking a carry on go through the terminal a security and take the skylink train You can't check bags in terminal A if you're flying out of another terminal

Walk in take the elevator up go out the sliding doors to your right. and wait for whichever terminal bus u need. Oh im sorry on a pole it will say terminal link outside

Get off at A go up to the ticket counter or check in at the self service kiosk, go thru security and catch the skylink to whatever terminal u need to be in. Very easy

Walk into terminal A and take the terminal shuttle.