Forgot to remove sim card and possibly sign out of icloud before selling! A couple of weeks ago, I sold an old iPhone 5. It hasn't been used for 3 years, and I can't remember what version of iOS it was running.

It just occurred to me that I did not remove the sim card.

I looked into it and apparently iPhone sim cards don't store any data, everything is stored on the cloud. That's fine. Then I realized that I don't remember actually signing out of iCloud!

I selected the erase all content and reset option. It asked for my password (I think twice) and maybe my 4 digit pin?

The phone erased within a minute and I saw the "welcome" page. 

I honestly don't know if I signed out of the cloud or logged out of find my iPhone!

I tried to gain access to iCloud online (I'm using android now) and while I have my apple ID and password, I had set up a 2 factor authentication to my phone number that no longer exists, as I cancelled the number when I changed provider and did not need the cloud as I'm using android! I also have no other trusted devices.

As far as I understand I can now no longer access my cloud.

I checked the find my phone section as it wasn't locked and it shows nothing? Maybe I did sign out of it, or maybe the phone is off?

As I said the phone definitely did reset, would it have automatically signed me out of cloud? And is the inactive sim card in the phone ok?

Feeling stressed out, what are the chances the person I sold to can access the content on the phone?
If you did a "Erase All Content and Settings" - then you have definitely logged the device out of your iCloud account. This function deletes everything stored on the phone, including accounts, app settings, app data, the apps themselves, documents, photos, etc.

If you had "Find My iPhone" enabled, the buyer of your phone would not be able to setup the phone without entering your username and password. I.e. they would have complained to you by now that the phone is essentially bricked. As weeks have gone by, it is far to assume that you either logged out of "Find My iPhone" or never had it enabled on this phone.