Ok. I tried to build it. There appears to be some errors in the setup of it. If you look in the .env-file there is a variable called PGPORT. I think this was set at 3000. But I changed it to 5432 which is a typical port for PG. This got the api connected successfully to the database. I should mention that I created the database manually through psql first and entered credentials in .env.
Then in the same .env-file there is a variable that was called (I think) PORT under Server-configuration. I changed this to SERVER_PORT and set it to 5000 (forgot what it was set to). If you look under /server/config.js you will see that SERVER_PORT is what is referenced from env-variables. This port needs to be the same as the one referenced in /src/setupProxy.js (under target) so set that one to 5000 as well (forgot if it already was 5000). This removed some api-proxy errors that were initially present.
Now if you go to /api/products it will return an empty array (no products in database table) and if you go to http://localhost:3000/ you should see a blue Codecademy Shop Nav-menu but it doesn’t do much more. I did not connect to Google/Facebook OAuth and I don’t see a way to make a local user account from Login Page. So let me know if you get any further!