Ready means you can deliver
Brands want a live read, a set of hours, a clip, or a banner, delivered on a date, with disclosure. Your media kit should show average viewers, a schedule, who watches, and three examples of you talking to camera without freezing. Twitch has also been opening more sponsorship and bounty-style offers. Check the creator side of the dashboard so you are not ignoring a door that is actually there.
Read the usage rights. A "quick mention" that lets them run your face in ads for a year is not a quick mention. If you are unsure, do not sign it between streams.