If you have upgraded iCloud+ plan, once your request for iCloud+ plan has been activated, you should receive an invoice in your email box.
Check -> Go to -> Settings -> your name -> iCloud -> if you see 50 GB (or 200 GB or 2 TB) then you have an iCloud subscription.
If you have an iCloud+ plan subscription, you will receive a monthly bill from Apple, check your email box.
Yesterday and today is not a business day. Check again on Monday.
See -> What's the difference between device storage and iCloud storage?
What's the difference between device storage and iCloud storage? - Apple Support
See also the following Apple articles:
How to use iCloud on iPhone -> How to use iCloud on iPhone – Apple Support (UK)
Manage your iCloud storage -> Manage your iCloud storage - Apple Support