Before building/running, copy .env.example to .env in the root of the project and update any values that apply to your project.
If npm run get:schema seems to hang - check your graphql_schema.json file. If it is asking about installing get-graphql-schema then you need to CTRL+C to break the install and try running just npx get-graphql-schema by itself. That will get you the prompt to install, and once installed you can run get:schema.