Creating online journal for my members

Hello,

I’m pretty new so bear with me, but I have an issue I can’t seem to get solved. I need to have a members area on my site where each member can have their own journal to record their progress in. It would be GREAT if they had the option of making that journal public or private. Can someone ANYONE please help me with this. My whole site depends on this feature. I’m hopping there’s some type of plugin I can use, or something. I don’t want my members to have to navigate off of my site to some random online journal posting site.
GET CREATIVE, THINK OUTSIDE THE BOX!!!
I hope all of that makes sense.

Thanks ahead of time for your answers,
-David