The process should be similar to running one you have created yourself, clone it locally, run the npm install or yarn to install the node_modules, and run the npm run develop or yarn develop.
This of course also depends on the database settings the user set. Do you have a link to the project you cloned?
This will largely depend on the email provider you are using but there are various methods to do this either using the lifecycle hooks: Strapi’s documentation | Strapi Documentation
Or you can customize the users-permissions plugin: Strapi’s documentation | Strapi Documentation