Snap Caps
Hey, Drew. I am a big believer in dry-fire practice with snap caps. It's free; it's a great way to ingrain muscle memory, and if not done in excessively long sessions, its' fun.
I've never used the Traditions that others have recommended. I have always used Tipon. The Traditions might be better but they are also a bit more expensive. Amazon carries both, plus several other brands. I've watched videos in which people recommended A Zoom brand.
The most important thing is to get ones that have a spring in them so that the fake primer cap is free to move. That is what protects your striker assembly.
There are people who say that snap caps are not necessary, and that is true if you do not do a lot of dry-fire practice; however, the manual of arms for the XDs and XD Mod2 both warn that EXCESSIVE dry-fire can damage the gun.
If you have not done so already, you might want to look up "Dry-Fire Friday" on Springfield's site.
Again, welcome!