SIM card in new phone

An iPhone does not store any user data on SIM cards. If you had iCloud Photos turned on in your old phone and if your new (to you) phone was erased by the previous owner as described in What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support and if you set up the new phone using your Apple ID for iCloud, the photos will automatically sync to it when you turn on Settings > [username] > iCloud > Photos > iCloud Photos.

More information in: Set up and use iCloud Photos - Apple Support

There is no connection between SIM and iCloud photos. They will stay in iCloud unless you delete them.

Just ensure your new phone is set up with your current AppleID and they will appear on the new phone

If you want to give away or sell your old phone do not try to manually delete any data, go through this process:

before you sell your phone...

https://support.apple.com/en-us/HT201351