I too don't bother with these Tokyo passes. These passes may or may not save me money, but I just go for the simplest thing which is to use Suica or Passmo card. With that, you don't have to worry about purchasing single tickets each time, you don't have to worry about whether you're getting on JR, shitetsu (private above-ground train companies), Toei, Metro, bus or trolley. You don't have to futz around with cash at convenience stores.
There will be signs indicating where each train is headed. Both English and Jpnese. It'll be on the signboard at the station concourse, each platform and on the train itself. But beware that different trains in Tokyo going same direction on a particular track will often have different destinations. For example, if you catch the Fukutoshin line in Shibuya going northbound, then the trains' final destinations could be Kotesashi or Wako-shi or Hanno, etc, even though they're all headed up north on the same track for a while.
I think all these details are making it sound more complicated than it actually is, and increase your anxiety further. Honestly, just have a map/guidebook (eg, Timeout), arrive in Tokyo, get a Suica/Passmo card, and you'll manage. Every American person that I know (some of them fairly absent-minded) who's visited Jpn recently managed to get around and enjoy Tokyo.