How do I stop my dog from being aggressive towards other dogs on our walks?

About four days ago I adopted a dog from a local shelter and he seemed to be fine around dogs there but whenever I take him for a walk and he sees another dog he growls. Its so embarrassing and I do my best to hold him back but then I just end up dragging him. He almost bit another dog a few days ago! Im really worried. PLEASE HELP!

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia…).