To create a channel:
By default, every team gets a General channel, which is a good channel to use for announcements and information the whole team needs. To add more channels:

1. Select ***More options next to the team name.
2. Select Add channel.
3. Enter a name and description for your channel. You can build a channel around a topic, project, department name, or whatever you like.
4. Select Automatically favorite this channel for the whole team if you want this channel to be automatically visible in everyone's channel list.
5. Select Add.

Source