You've already been apprised of the legal issues, so let me ask you a few questions...
- How did you program the radios?
- Were the antennas screwed all the way in?
- What was the terrain like where you were testing these things? Trees, houses?
- How did you decide on squelch level 5?
- Did you modify the CTCSS settings on either of the radios? This seems like the most likely issue.
For future reference, though, an FCC ID is just a confirmation that the FCC knows what the device is (not really, but that's a different issue). It's NECESSARY for a device to have an FCC ID to be type-accepted for a service like GMRS, but not sufficient.
For your Ham license, check out hamstudy.org. Don't overblow the studying part. The technician test is so fall-off-a-log easy that eight year-olds routinely pass it, and the general test is still pretty much child's play to anyone with even a modicum of electrical knowledge.
Some of the old guys will tell you "You've got to learn the material!," and while that's true in principle,* you can only understand so much of the actual physics and engineering stuff before you get deep into serious electrical-engineering territory. It's the kind of stuff that you just can't understand without either a long time of tinkering and experimenting and fooling around, or dedicated academic study, or both. So just focus on learning the rules and safety procedures, and just drill-and-kill the rest of it. You'll learn it later as you go.
As a matter of fact, these are the four most important rules in electrical engineering:
E = IR
P = IE
For capacitive circuits, the current leads the voltage.
For inductive circuits, the voltage leads the current.
In the words of Hillel the Elder, that's the whole Torah, the rest is the explanation; go and learn.
* No disrespect intended to the Old Guys; they're the keepers of The Ancient Knowledge, but a lot of them are, by training and profession, hyper-experts in extremely abstruse and arcane fields like RF propagation physics or microwave circuit engineering, so "learning the material" by their standards is an extremely high bar by almost anyone else's.