I'm not sure how it is in Ireland, but for your neighbors to complain, it must be significantly annoying.
I think you really need to go out with the dog, and correct the dog for barking, or go directly back inside the moment he starts up.
Training classes will help teach you how to teach your dog things. Those things will be certain basics in class. But the methods of teaching can be applied to other stuff as well. And, as you and your dog master the basics, the bond between you and he will help you to communicate to him what you want and what you don't want.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC