Training camp just ran and I don't see anything different really in my players. Can someone explain to me what happens in training camp and what I should have done to prepare for it?

Thanks!

Training camp is actually a pretty simple sim, you don't need to do anything special for it other than it's your last chance to get your players that you signed during late free agency into their final positions before they go to camp. At camp they will learn the playbook, increase their conditioning, and improve their attributes.

I did just notice a bug after your comment where the progress graph is one stage behind, the training camp update is not being displayed until pre-season week 1. So to see the progress for now you can compare what the graph says to what is in the header on the player page, or wait until the pre-season game stage on Tuesday for the graph to catch up.