Depending on what town you move to, the PD might require three letters of reference. Do NOT do this as a town can NOT require anything more restrictive than the state (pre-emption) and, according to the BFPE (the people that issue permits), not providing them can NOT cause a denial or delay in the issuance of a permit. It's just a bullshit scare tactic technique that adds another level of complexity in the hopes that people won't get their permits because it's too much of a PITA. After all, in my case, when I was a new resident, whom did I know well enough that they would write a letter endorsing a guy to carry firearms concealed whom they barely knew? All I knew at the time was a few neighbors and co-workers and they, at the time, were the LAST people I wanted knowing I owned firearms. Can't use relatives.
Here's another tip. They want your boss's name and phone number on the application. Since the spot after your boss's name only says "office phone", I gave them my number. That way they wouldn't my boss wouldn't get a call out of the blue regarding a new employee from the state police asking about firearms. If they called me, I'd tell them he was busy and to call back later. That way, I could pull him aside and discretely explain why he'd getting a call from the state police about me. But, they never called...no voice mail. Anyone had their place of employment called when applying?
As for the training certificate, if you're prior military, a DD-214 will work. I used my years old certificate from the class I did at Gunsite in Arizona. Worked just fine.