[2/4] Fetching packages...
error An unexpected error occurred: "G:\\yarnConfig\\yarn_cache\\v6\\npm-serialize-javascript-5.0.1-7886ec848049a462467a97d3d918ebb2aaf934f4-integrity\\node_modules\\serialize-javascript\\.yarn-metadata.json: Unexpected end of JSON input".
清理一下缓存试试
yarn cache clean
npx create-react-app