Can someone point me in the right direction?
That way! No, no, the other way.
Some context about your application(s) would be useful.
How would I program the arduino to control servo #2 instead of servo #1 or led #2 instead of led#1 when a button is pressed on the android app?
When a button is pressed in the Android application, what are you sending to the Arduino? How is the Android application supposed to know whether the data is for servo/led/whatnot one vs. servo/led/whatnot two?
If there are two buttons/sliders/input fields/whatnots on the Android application, one for each servo/led/whatnot, then the data sent to the Arduino should reflect which button/slider/input field/whatnot the data came from, and the Arduino should use that to determine what servo/LED/whatnot to apply the data to.
It ain't rocket surgery.
Do I use char, for loop, strings, bytes, events?
Yes. Wait, no.
Im lost.
I've got a map here. I'm willing to tell you where to go.