just cleaned out some files off my computer. idk what I'm missing

LambdaSr167sMBP:~ lambda_school_loaner_167$ yarn add create-react-app

yarn add v1.22.4 info No lockfile found. warning package-lock.json found. Your project contains lock files generated by tools other than Yarn. It is advised not to mix package managers in order to avoid resolution inconsistencies caused by unsynchronized lock files. 
To clear this warning, remove package-lock.json. 

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