I just had a little peep and i can see that you have just registered today on 18-01-2019 at 13:24, so please dont worry this is the usual procedure, it can take a few hours and in some cases upto 24 hours, its always a good idea to restart your phone every hour or so.
You will be up and running in no time.
I hope this helps ,and good luck.
Activated my SIM card and the mobile data isn’t working?
Access Point Name. giffgaff.com
Password. Leave this empty ...........
check on your coverage.https://www.o2.co.uk/coveragechecker.
Activations can take as little as 30 minutes - 24 hours to complete.