I have a new field I created called Client lead Source.  I would like to name that field required based on 2 other picklist fields called "Primary Lead Source" and "Secondary Lead Source".  Once the picklist value for both is equal to "Client", this new field would be required.  I am not exactly sure how to accomplish this.

I want to create the following formula field, but I am not sure how to go about doing this:

If the picklist of "Primary Lead Source" or "Secondary Lead Source" is equal to "Client", then the formula field should display the Account field called "Account(Display)".  The Account Display is another formula field that combines Account Name, Organization Type, and State. 

I am working on an IF statement for tasks.  If the status picklist is equal to completed, I want the due date field to automatically update to todays date or to throw a message that says the user needs to update due date to today.  This is what I have so far.  Can somebody assist me?

IF (ISPICKVAL(Status, "Completed"),
ActivityDate=TODAY(),NULL)

I have a new field I created called Client lead Source.  I would like to name that field required based on 2 other picklist fields called "Primary Lead Source" and "Secondary Lead Source".  Once the picklist value for both is equal to "Client", this new field would be required.  I am not exactly sure how to accomplish this.

I am working on an IF statement for tasks.  If the status picklist is equal to completed, I want the due date field to automatically update to todays date or to throw a message that says the user needs to update due date to today.  This is what I have so far.  Can somebody assist me?

IF (ISPICKVAL(Status, "Completed"),
ActivityDate=TODAY(),NULL)