Hi Annette. Welcome to justanswer.
Can you please specify which device you are using with brand and model details)?
Have you tried selecting the network manually?
Go to Settings. Select Mobile and Networks. Then search for the available networks and select your home network manually and then check.
And also tell me if you are receiving any signals or not?
Not network modes. Select Network operators. Then you will get a list of networks available. Then select your home network and check
Turn off the phone and remove the sim card. Then again put it back and then check.
Do you have any other phone with you right now? If yes, then connect the sim into that phone and then check if the problem is same in that phone also?
Have you used this sim before?
Which network are you using?
You should contact O2 as they have not yet activated your sim card. This is not a fault of your phone. Just your sim hasn't been activated yet.
Yes you need to do that only. Just tell them that you have bought a new connection with this number and it has not been activated yet. They will activate it and you will then get the signals on your phone. Your issue will be resolved then
You are welcome Annette. Please let me know if you get any difficulty. Have a wonderful evening.