How do check if you got an friend request Or been invited..ect
1) It depends on how you're accepting friends, if your setting is set so you have to approve people to be your friend a notification will be sent (which I'll explain after) but if you have it set so you don't have to approve they'll attomatically be accepted as your friend. To check which setting you have you can go to your 'Friend Management' which is in your settings: http://www.funadvice.com/my/friend_manage
2) In order to receiving an e-mail when these things happens you'll have to have your notifications turned on, to turn those on, if you haven't already, you go here: http://www.funadvice.com/my/toggle_notifications (except if you're invited to a group you'll get a FunMail)
When you check your funmail it should be a link. click on it and you'll be added to that person's profile.