Craft CMS 3 storage doesn't exist or isn't writable by PHP
I'm on Windows 10, so if you're on another version of Windows, things might be slightly different.

If you right click on that "storage" folder, go to Properties, click the "Security" tab, click "Edit", click "Add", type "Everyone", then click "Check Names" so it finds the user (an underline will show up under it), click "OK", make sure "Everyone" is selected, then check the "Full control" checkbox under permissions, click "OK", then "OK" to close the final modal, that will give everyone access to write to that folder (including PHP/Craft).

Obviously, don't do this on production, but since you're on a local box you should be fine.