When you buy the "B.FREE Breitband Welcome Package" (for EUR 14,90), you do not have to recharge it before use - it comes with 1 GB of data.
I suggest you go to an A1 store to buy it - other stores may not have it.
This sim card is not intended for outgoing calls (it is a data tarif). I am not sure if outgoing calls are working. If yes they are quite expensive.
Incoming calls are free.
Don't forget to set up a data profile on your mobile for internet access:
APN: A1.net
Username:
ppp@A1plus.at
Password: ppp