Can I listen to XM radio through iTunes?

No. Doesn't that come over the "airwave"? iTunes plays content that is stored locally, or accessed over the Internet. iTunes does still have its old streaming (no cost) "Internet Radio" feature (not to confused with the Radio feature of the subscription Apple Music service), that plays content from radio stations.

It is a bit hidden in the current iTunes. In the horizontal bar that goes across the iTunes window, find the "three dots" (next to the buttons for Music, Movies, TV Shows, Podcasts, etc.). Click it and select Internet Radio, to show the Internet Radio button on the bar. Click that button to get a listing of stations that stream their content.