My uncle passed away and I got his compter given to me by him

Im nearly 10000% positive He had lots of bitcoin from playing mafia wars way back when they handed out bitcoin like candy on fb. I have access to his email and full access to the computer. Someone guide me where to start to find this shit. He had lots of money before he died from neuropathy he literally spent over 20k on his favorite cell phone game months b4 his passing. I know without him ever telling me he had a fat stash of coin by the way he was recklessly running through cash and always talking about how much misses the mafia wars days. Help me out!