clients private page

Hello, i have a client who wants me to make different pages for different users and each of them will be able to access his page only after he puts a username and password.
Then in his page, he will be able to download pdf files or have access to his private information.
The problem is that i dont know how to do this, as i am new in web design and wordpress.
I dont know how to connect each client private page with his exact login information.
Is there a plugin? I found some but they give access to a specific private page, not each person to his own page.
Can you help me out here? Thank you in advance… Sorry for my english, i dont know if i make you understand.