Not receiving Telerivet SMS to CiviCRM
For sending sms, the contact should have Phone number of phone type as 'Mobile' and Primary as true. The option will be visible once you set required phone type. 

The incoming message will be shown under Activity tab of Contact of Activity type as Inbound SMS. You can also check using Activity search with filter Activity type as Inbound SMS. You can also create Activity report with with filter Activity type as Inbound SMS and have it available on dashboard.

HTH

Pradeep