Welcome to Maine. Our laws are pretty firearm friendly, though some of our towns are not so much. Remember, the law is on your side so you can fight any harassment you receive. Maine requires no permit to Open Carry loaded or unloaded. If you don't have a CCW permit, then you must unload when in a vehicle.
If you are on private property such as a business, and they ask you to leave, you must comply or you're trespassing. This has only happened to me once or twice in the last 4 years of OCing in Maine.
We have full State Preemption so no municipality can regulate carry of firearms in any way (Though they can limit the discharge of firearms)
I look forward to meeting you at one of our functions.