Delete yarn_lock.json or rm -rf yarn_lock.json (if you are Linux/MacOS user)
Delete node_modules/ or rm -rf node_modules/ (if you are Linux/MacOS user)
Follow the instructions to install the latest Yarn package available from here
Try executing following commands in your project root folder:
yarn install and yarn start
In case if the above approach didn't help:
Try to install latest node.js
Remove node_modules/ and lock file
use npm install and npm run-script