Settings, bottom-left. Then drop your signature in.
From the dashboard, click Settings at the bottom of the left nav rail. You land on My Profile. Scroll to the Signature card. Paste in the signature you already use (Outlook, Gmail). Click Update Profile to save.
Flip the toggle. Every email signed automatically.
Same card, top of the editor. Toggle on Enable signature on all outgoing messages. Click Update Profile to save.
Connect your email. Stop switching tabs.
Same page, right column. Find Email (2-way sync). Pick Gmail or Outlook, whichever one you actually use. Click Connect and authorize.
Connect your calendar. One source of truth for your time.
Different page this time. Click Calendars in the left nav rail. Up top, click Calendar Settings, then Connections. Click + Add New and connect Google or Outlook.
That's the home base.
Your signature is set, your email is synced, your calendar is connected. The system stops feeling like someone else's software and starts feeling like your desk.
Five minutes here saves you from a hundred small frictions in the next year.