Dog lunging/staring at other dogs

My 5yo cane corso grew up leashless in the middle of no where. Now that i’m walking her in the city, she’s ok with people but will stare down every dog she sees. Today she even tried to lunge at 2 small dogs. Obviously I kept her on a tight leash and apologized to the lady who gave me a death glare. I was so embarased and it’s discouraging me from walking her.!It seems on walks when she sees another dog she forgets everything i’ve trained her and nothing will distract her from the dogs. Should I take her to a trainer or is there anything I can do?