Uhm.. are you on a Work Computer? Or maybe a School computer? Does it 'SAY" site is blocked? Or is it just not coming up? Have you tried with another web browser (Chrome, Firefox, IE) then the normal one you use? Did you try the SAME FB page from another computer just to make sure your FB page didn't get taken down?
are you behind a proxy? (at work, school or on a public wifi?)
if so then we cannot help you bypass it.
if you are not behind a proxy (your own home network) then you ned to give us details such as:
-are you the owner of the network (if not, could someone have blocked access.. and if yes then talk to the owner)
-was it working before (ie maybe facebook had downtime or perhaps you blocked it accidentally somehow)
-anything else which you think is relevant.