Help Creating a Client Portal

I need some help making a custom client portal on my Wix website where clients can login into a client profile and then be able to send us secure private messages. I also want it so that they can upload documents and be able to see details about the services they have ordered from us.
Does anyone has any suggestions on client portals and how this can be done?

The article Velo Tutorial: Building Your Own Members Area should be able to give you a start in the right direction.

I want to know too!

See the link already posted above.