How to Create an Organisation
From the Dashboard select the Organisations tab on the lefthand menu.

In Organisations select the +Create Organisation tab on the top tool bar.

The Create Organisation pop-up will appear. Enter the company name and click Create Organisation.

The Organisation profile will show where you can allocate an owner, Industry Sector, Sector, Lifecycle. You will also see any Contacts' thumbnails who are connected with the Organisation, past or present. Logos can be added to the Organisation profile.
Read here:
How do I add an Organisation Logo?

The basic Organisation creation is complete.