I got a blackberry curve 3g i got a blackberry curve 3g few days ago but it dosnt let me go on my bbm?

so it doesnt let me go on my blackberry menger and blackberry app worl i asked my friend how she did it on her fhone she said that you had to ring up what ever network you were on so i did but they were going to charge me but how *** my friend didnt ge charged and if you now any wY TO DO SUMMTHING pleassss tell me (btw my network is 3) (and when ever i go to blackberry app world it says blackberry app world is havinf trouble connecting to the blackberry app wprldd server . verify your network connections and try again ) pleasse helpp meee thank yeww hope you doo :P