Directly from the SDA classroom material provided by CLEET:
"NOTE: It is unlawful for a person with or without a license to carry a concealed handgun into places where such actions is prohibited. There is no Oklahoma Statute which requires that a sign prohibiting firearms be posted on the building. The SDA Concealed Carry Permit holder is expected to know the law."
Also mentioned again as follows:
"NOTE: This statue is the subject to many complaint calls to CLEET. Concealed Carry Permit holders are upset that they cannot carry their firearm into a certain business. The solution is simple – if you are unhappy with the policy of that business, do your business somewhere else. The business owner’s rights to prohibit weapons from entering the business trumps the Concealed Carry Permit. There is no Oklahoma statute which requires the business to be posted with a “no firearms” sign."
This should have been read to you by your instructor as it is specifically noted in the curriculum for the class.
Your first quote looks to be to reference "prohibited places" listed in §21-1277, not 7-11 with a gunbuster sign.