Hi @Marie_Ross,
welcome to our English Community. Nice to meet you here.
First of all, I would like to ask you, not to write several messages for the same topic.
I just have read that you have an o2-prepaid card. Did you already activate the card? If not, please follow the steps described here: Activation of your prepaid-card Just switch the language into English there.
Afterwards, follow the steps described here under the point “Transferring your phone number to o2”:
I hope the information is helpful for you.
Loving greetings,
Tobias