How to create a hover state

Hovers need states, which are provided by components in Framer. Draw a new element and select Component → Create Component from the menu. You'll now end up on a separate isolated component canvas. Click the Hover / Pressed outline on the canvas and select Hover:

Now you can visually tweak the hover state for your component however you like. You can preview it on the main canvas within the context of your entire project, or in isolation to see it just by itself.