Thanks for joining us here @Android Forums. You can get the Facebook for Android application from "Google play" (market), and there is where you get Skype as well. If you have never used the market before - you will need to sign in with your google username and password.
Also, here is a link to your device's support forum Samsung Galaxy Ace - Android Forums
. Where you can interact with other users of the same device. There are lots of info, hints, tips & tricks on your device.