An Office 365/ Teams account needs to be submitted and approved by your Department Director. 

If approved, request an account here.

You can use Webex Meetings outside of VPN for the best experience. Close background applications. Even if you’re not using them, applications on your device are using precious resources.  Learn More

When you need to communicate and collaborate with people outside your organization, Microsoft Teams gives you two different ways to make that happen. Please review this article.