first open your terminal in the client and server folders then in each one execute
npm install
Create a postgresql database using the .sql file inside the server folder.
Add the next variables to your server enviroment.
DB_USER=*YOUR DATABASE USER*
DB_PASSWORD=*YOUR USER PASSWORD*
DB_HOST=localhost
DB_PORT=*YOUR POSTGRESQL PORT"
DB_DATABASE=groupchat
SESSION_SECRET=secret
now in the server folder execute:
npm run dev
and inside the client server:
npm start