If you have the Deadlock Graph - you have quite a lot of information. Reading the deadlock graph takes a bit more skill. But not too much. The graph is showing you what a deadlock is. It's sort of like when two cars are at a point where they each need to cross a road to enter a parking lot across the street from them at the exact same spot. Say they each want to make a left turn. Car A can't take a left because Car B is in the way. Car B can't take a left because Car A is in the way.
SQL Server just blows one of the cars up for you instead of moving one of the cars a bit or driving around the other.
But I digress. The deadlock graph information and the rest of the info in the deadlock report will show you which object each session have locked and what type of lock - and also what lock the other wants.
You may see some query info, may not depending on a few things. But if you can recreate the situation you can capture some of the query info from an extended event session or a third party tool that watches queries coming in - tools like Sentry One, Idera DM or Solar Winds DPA should all show you queries as they happen - and most have a free trial period. Sentry even has their own deadlock graph, I trust the others do also but not sure.