I can never get React.JS sites to run on development servers via terminal

Hi,

I have this problem with every single React.js Template on envato elements. I don’t have this issues with my personal projects or other templates I buy from walk through videos. I can just start/run them via npm or yarn usually whereas this never works when i get it from Envato.

TLDR: I can never get any of the react.js templates to run of my local host via terminal. Assistance would be great, thank you.

Would need to see some error messages to get an idea for what could be going wrong. Do you happen to have any?