My eBay: Purchase History only goes back for the current and two prior calendar years.
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...
As for an "invoice" the information will be basic (seller, price, item title, item number, your max bid if it was an auction and the like). I assume you are not asking about seller fee invoices since you are asking on the Buying instead of Selling board.
