Go to Supporters. Each row is a person (usually keyed by email) who has given or been added to a list.
You can:
Filter by campaign and date range
Sort and switch cards or table view
Open a supporter for profile details and gift history
See total given for the current filters
Supporters appear after the first completed donation (or after an API/list import). If the page is empty, create a campaign and collect a gift — or add people to a list under the Lists tab.