I was given .1569 bitcoin as a gag gift years ago. I happened to see it in the safe (piece of paper). After much frustrating research I determine that Electrum is the wallet to use...
You didn't really research anything, because if you did that it would not take you even 16 hours to figure out the basic units of Bitcoins. It takes 30 min to maybe 1 hour to understand how Electrum works, there is how to do step by step in
Electrum FAQ. I admit there is no mention of mBTC in FAQ or how to change that to show BTC or fiat value, and this should be enabled by default.
Just do not panic and rush with sale, maybe you can profit more since price of Bitcoin is going up this days. Amount you have is currenty worth $1685, in few days it can be $1785, so keep that in mind.