There are sites that host games, updates and DLCs for Switch games and alike, but you'll have to find them on your own. We are not allowed to link to such sites around here.
Provided you have the latest Atmosphere, Hekate and sigpatches on your Switch, once you download your games to the PC you can use DBI Installer in order to install games from your PC to your Switch. Here's a good video explaining its features in case you need it.
