My Dog Always Barks At Dogs When Were On Walks, The Only Time He Doesnt Bark Is When A Dog Barks At Him!?

hes a german shehperd greyhound crossbreed, and hes just over a year old. we got him at a shelter and hes always been hyper, but hes neutered as well and it hasnt helped with his barking! when I try to get him to socialize he will be overly excited and will scare the dog AND after a while he will start to growl and bark! if i take him to petsmart or a place like that for training, i know hes guna go CRAZYY and bark the whole time, not safe at all because hes so strong! PLEASE HELP!!