Hi good morning!
I'm from Brazil. recently I created a website for a client the client asked me to I create a login for students entering your name and password to download the report card trough a link to pdf. could the couch working with it?
Help me, please

I just noticed that your question got overlooked by the forum. Sorry about that.

Yes. Couch can do what you are asking, but it involves some of the more advanced features of the CMS. The "Extended Users" Module will allow you to create the sort of login capability you are seeking.

You can learn about how to use it at:
http://www.couchcms.com/docs/extended-entities/post.htm