My eBay: Purchase History is where to look, but it only goes back for the current and two prior calendar years and only shows those for one particular year (or the past 60 days) at a time (select which at top right of the Purchase History section). You joined in 2020 so it will not display any purchases for that year. My eBay is linked at the top right of most pages (on these community pages, as opposed to the main buying and selling sites, you can click your icon at the very top right and it's in a dropdown menu).
You can make a special request for a report of your purchases (and/or sales and/or lots of other information) for a specified time period back to the creation or your account (and possibly any guest transactions if you provide the right data): https://www.ebay.com/help/account/requesting-personal-data/requesting-personal-data?id=5089&st=12&po...
