Hey @Lizsstuff1!
When you get your new SIM for a new line, it's already active. Just pop it in the phone and you're good to go 
If you were looking to transfer over a number to replace the one we gave you on that new line, then please contact us to request a port-in of your number from another provider.
Hello @srii,
Welcome to the Community!
Did you already have a SIM card before receiving your new phone?
If so, the previous one would be the SIM card that is currently active on your account and you can use that one. If you wish to use the new SIM card, you would need to change it on your online profile. You also need the old SIM card to be able to do this. If you don't have the previous SIM card, you will need to go in store to get this updated.
Hope this helps!
@Antonjm wrote:
Pretty self-explanatory, thanks for the help!
Hello Antonjm,
Welcome to the forums!
Hmm, are you saying that activating SIM card online was self-explanatory and you were able to do so? Or that the title explains what you want help with?
Assuming it's the latter, if you go to My Account --> Select Mobile (or select line if multiple lines) --> Update SIM card --> Enter new SIM number
Hope this helps
Cheers
