From Full stack cours front and back end angular-nestJs

Question

The cours started from angular passed by typeORM to NestJS! My problems is TypeORM section! When it said { import it (import reflects-metadata) in our main file}, first we are from Angular going to NestJS. meaning, we know nothing about NestJS. So the installation {npm install typeorm SHOULD BE INSTALLED WHERE? In angular project modules or completely out of the angular project folder? Secondly: WHERE TO INSTALL The ( npm i reflect-metadata) and which is the mean file where the import of reflect-metadata should be imported?
Thirdly: where the npm install pg should be?
Fourthly: in which folder or file should be (the connection script : ( import { createConnection, ...} from “typeorm”;
Const connection = await createConnection({.......)})
SHOULD BE ? Pls I’m really confused! I need your help friends!!!