You can jump to a particular Team or Channel by using the Go To shortcut: Control + G. Start typing in the Team or Channel name and Arrow Down through the results. Press Enter on the one you want.
And here’s a little explanation from Microsoft on what are Teams and Channels:
- A team is a group of people gathered to get something big done in your organization. Sometimes it’s your whole organization.
- Teams are made up of channels, which are the conversations you have with your teammates. Each channel is dedicated to a specific topic, department, or project.