Dipping Your Toe into G Suite
A full-on email and calendar migration is a daunting task. When I converted my former employer from in-house Exchange over to G Suite/Gmail, it was a six-month project involving about two full-time employees (side note - our massive email archive was the "long pole" in this project). If you'd like to dip your toe into the G Suite pool, before embarking on a full conversion, I'd suggest initially using G Suite to replace WebEx/Zoom, Slack, Box.com, and Visio/Lucidchart. At just $5 per month, the cost of G Suite is minuscule compared to the combined cost of those products.
G Suite as a WebEx/Zoom Replacement
Using Google Meet for Web Conferencing
To schedule a web conference in Google Meet, follow the steps shown below, and paste the meeting info in your Outlook meeting invitation.
Using Google Meet as a "Meetup"
To create a static link for your team to use on an ad-hoc basis, see below. I call this a "meetup", but if you're old enough, you might call it a "party line". :-) Once created, you can IM teammates, and say something like, "can you join https://meet.google.com/xxx-xxxx-xxx for a quick discussion?" Once your team gets used to it, you can just mention the last three characters of the meeting id, and they'll know what you're talking about... or just say, "can you join the party line?"
Note that if you have a daily standup meeting, you can just use that Google Meet URL as your "meetup"; therefore, you don't have to create a separate, dummy "meetup" meeting. Just use the Google Meet URL associated with your daily standup meeting.
G Suite as a Slack Replacement
Using Google Chat for IM Collaboration
Google Chat is definitely not as "hip" as Slack, but the basic features, like channels/rooms and bots, are there!
G Suite as a Box.com Replacement
Using Google Drive for Document Sharing
Unfortunately, you can only securely share documents with other Google users, but who doesn't have a Google account nowadays!?
G Suite as a Visio/Lucidchart Replacement
Using Google Drawings for Flow Charts
Lastly, why pay $250 for Visio Standard or $6/mo for Lucidchart when you can use Google Drawings, which comes with G Suite and all its collaboration goodies!
Here's a pro tip - You can do almost everything in Google Slides that you can do in Google Drawings and more; therefore, I prefer to group related drawings in Google Slides. For an example, see this post.