You haven't really asked a coherent question yet, so I'll assume that you don't know which direction to go. If you don't want to make dumb mistakes, then the first question is "What is your goal?"
If it's performance, the smartest move is to ditch the extended cab and get a RCSB. That's hard to hear when you're young and broke.
If you're wanting to pick up dates, they don't care much if your truck is lowered or has a bumping stereo. They care if it's clean, runs good, and doesn't look embarrassing.
If you want to lower it "just because", that's fine too. Just know that it makes it harder to work on your truck. Right now I can just slide under my truck and work on it.
If I were to do a 5/7 drop, I'd cut a single coil off the springs and install dropped spindles up front, and an axle flip and drop shackles in the back. It'll be a little stiffer up front, but it won't kill the ride quality. This may only get you to 4/6, but it's a good start that's relatively inexpensive and avoids dumb mistakes.
Note that some dropped spindles widen the front track. This matters for wheel selection if you install wider wheels.