All protein is is a chain of amino acids. there are 20 amino acids...11 of those are produced in your body. The ones that are not need to be derived from food sources. The protein sources which contain all 9 amino acids are called complete proteins. Meat is a complete protein, whey is a complete protein. Black Beans or brown rice on the other hand have protein, but they are not a complete protein on their own as their protein chains don't contain all 9 essential amino acids. Pair them together, then it is a complete source of protein. So unless you're simply not eating enough protein, there is no need to overthink the distribution of amino acids.
Vegetarians and vegans are at highest risk for having a deficiency in essential amino acids.