How to locate completed tasks in Camunda EE?

Hi,

I have downloaded the 30-days trial Enterprise Edition and repeat the action. I still could not find the completed task anywhere in the system using all the available credentials. I have a few difficulties to locate the tasks.

Is there a way for me to view the following from the system.
a) How many tasks created and by which user ?
b) As a non-admin user, How many tasks in progress ?
c) As a non-admin user, where to view the current task at which stage ?
d) As a non-admin user, How many task has been completed ?
e) Where to view changes/log for each task ?

Thank you.