To send an email campaign, go to campaign and then click on Send Campaign. On this page, you will see a button on the top right in green colour "Create Campaign". Click on it.
This will open a form and you need to enter the following details Campaign name, select the contact list, Subject line and Sender Name and then click on submit
Now, you can select the template and decide when to send the email to your database.
Just to add here, the Email template and contact lists are precondition here. Before you decide to send any campaign, make sure the email Template is decided or created and also the Contact List is ready.