Before starting the setup, please use make sure you have proper tools
node -v v12.8.1 npm -v 6.14.9 ionic -v 6.12.2 cordova -v 9.0.0 java -version "1.8.0_171"
Are you new to ionic ? Before doing setup, you can follow these tutorial
Once you’re able to up & run your sample ionic app, you can continue with next step