A data grid can have no selection, single selection and multi selection. You need single selection, that is the default setting. All you need to do is to add a button that opens a page or calls a microflow (if you need more logic). The selected object is automatically passed to the new page/microflow.
I assume you have a Package entity, Account(Customer) Entity and a Wishlist Entity if not add them.
The relationship between Customer and Wishlist is 1 - 1 each customer has a wishlist and a each wishlist belongs to one customer.
The relationship between WishList and Package is * - * a package can be in many wishlist and a wishlist can have many packages.
Now when a customer clicks on a package 1st page , associate this package to his related wishlist if exist, if not create a wishlist object for him and connect the Package with it.
On the My Wish list page, Get the wishlist by Customer in a dataview, inside it display packages by association with the wishlist or xpath 'currentObject' inside a datagrid.