"Code" in the sense of a programming language is always an uncountable noun: "his own code", never "codes". In your sentence it's probably better to say "his code" and not "his own code". You probably mean "Otherwise, you will both be confused." "Either of the freelancers" means there are two freelancers, and one of them will be confused. There are other minor errors (not many) and you might have better luck putting this into Notebook for correction, rather than Answers.