Seperate organizations using one crm

Any advice on how to separate leads and views for different sales people?

I thought to create different modules, however modules don't have fields such as first name, last name etc...

I thought by creating different modules, I could create different tabs that would be able to show the difference.
Otherwise, there is a default view?
Also how to separate leads by lets say a service line for example? I thought the territories would do this, but its not a great solution?