In Toki Pona, all proper nouns external to the language are adjectives. This behavior of the language is on pages 37 to 39 of jan Sonja's Toki Pona: The Language of Good, where she gives examples of proper nouns transliterated into Toki Pona. In jan Misali's 12 Days of sona pi toki pona series, he gives the example of "jan Robert": here, the word "Robert" means "a thing named Robert". Since all proper nouns behave as adjectives in this way, they must follow a word that indicates what kind of thing they are. People are generally "jan [name]". Places are "ma [name]". Most curiously, languages are "toki [name]". I'll be focusing on the last of these.
Here are some examples to get the point across:
In each of these cases, you transliterate the language's name (endonym) into Toki Pona and that becomes an adjective. To specify that these are languages, we refer to them as a kind of "toki". "toki Inli" is "a language named Inli (English)".
Given this behavior of Toki Pona, there are some interesting ways we could misinterpret Toki Pona's name, which are all subtly wrong in funny ways.
"Toki Pona" is a single proper noun in English. To refer to it in Toki Pona, call it "toki Toki Pona". You should alter each word to not overlap the language's actual words, "toki" and "pona". For fun, I would call it "toki Toka Poni". I would prefer the spoonerism "poki tona", but "poki" is already a word in Toki Pona.
"toki pona" is not a proper noun at all, and as a subject or object refers to some contextually specified simple or good language. Toki Pona is nameless!
"toki Pona" refers to a language named Pona. Pona is an adjective meaning "a thing named Pona". Again, you alter the name so that it doesn't overlap with an existing word in Toki Pona. "toki Pono", or whatever it is? Give me a break.
"Tokipona" is intended to be a single word, and may be referred to as "toki Tokipona" so long as you stress the first syllable as hard as you can and whisper the rest. Also, make sure to speak the remaining syllables as quickly as possible.
Toki Pona is not a language, because you cannot faithfully translate anything into or out of it. The mark of a language is, of course, the ability to perfectly represent information in it without altering the original meaning. Thus, Toki Pona should be referred to as a kind of "ijo" out of disrespect.