How to deploy a project?

Question

PostgreSQL

Hello everyone, there is an application on react + node.js, I also use postgreSQL in the project
. I had a problem with how to put it all on the server and make it work. At first I uploaded a database to heroku, now I don’t know what to do next, and I just have a couple of questions about
this path directed them there, what should we do now, that is, where should they be saved now when added to the server?
2) How to connect react and node.js with postgreSQL on the server, am I going to post everything on heroku?