Method 1: Open Teams and click on the Calls tab. Click on the New Call button. Type a number using the dialpad and click the Call button. To pick someone by name instead, tap the People tab in the top right, search for a name, and click the Call button next to their name.
Method 2: Open Teams and click on the Chat tab. Click the New Chat button, enter someoneās name, then click the Call button.
Method 3: From any place in Teams, click someoneās icon (usually their initials inside a colored circle) and click the Call button.