不允许用户“用户名”@“本地主机”(使用密码:YES)进入C:\webdev\wamp\ wamp\www\membershipSite\classes\Mysql。php在第9行

I'm new to all of this but I do know a decent amount of HTML/CSS. I want to create a login server and I got most of the code from a video. If someone could help me and explain thoroughly so I can understand it would be greatly appreciated. If any other stuff is needed I will gladly post it. I'm new to all of this but I do know a decent a