Head to Joel's House
After the scene has concluded, exit the cemetery and head into the Joel's home on the right. Here you'll want to interact with the cup in the kitchen to add an entry to your Journal, then head upstairs and interact with the guitar in the first room you see to add another entry to your journal.
Leave the room and go into Joel's bedroom to find a red box on the bed, interact with it to acquire his Watch and Gun. Finally, go downstairs and speak with Maria before heading to Seattle.