In administration panel go to Configuration => Configure modules
Select Inquiries module
If you want to hide prices of all the products than in administration panel go to Configuration => Products configuration.
Select Hide price.
You can use import / export feature to hide prices and select an availability for the selected products.
Check out security documentation.
A message will be send to shop's main e-mail account:
In administration panel go to Sale => Inquiries
Select List
Customer will receive an answer:
Check out changing a header and footer in the e-mail messages documentation.
Select Statuses
Default status is set for each new inquery. Only status type New can be set as the default status.
Change Language version to start editing a record for the other languages.