Problems with cloning a react app from github

I am pretty new to javascript and react, I want to use this github https://github.com/bennychen27/LoL-Stats-Tracker.

I use Visual Studio Code.

How I tried it?

1. Downloaded the App as zip
2. Unpacked it
3. I have seen that this project includes a proxyserver and a client
4. Then I have seen, that there are in my opinion files missing within the client folder, because how I have learned, the proxyserver and the App have to get started in two separat Terminals.
5. So I have opened the unpacked folder in my visual Studio
6. I used npm install in the main directory
7. I deleted the client folder
8. I created a new client folder by using: npx create-react-app client in the main directorty 9.Then I replaced the files in this client folder with the before deleted files of the before deleted client folder
9. I restartet my Visual Studio
10. I used npm install in the new client folder
11. Then I added the line "proxy": "http://localhost:4000", in the package.json file of the client, because the server runs on port 4000
12. Then I used npm start in the main diectory and the client folder
13. Then the proxyserver started without problems
14. And the client showed this error The react-scripts command is either misspelled or could not be found.
15. So I used npm install again to fix that.
16. Then I used npm start in the client folder
17. Then the error 'React' must be in scope when using JSX showed up
18. I added import React, { Component } from 'react'; in my app.js file
19. A new Error showed up Module not found: Can't resolve 'moment' in .... Failed to compile.
20. I used npm install --save moment npm install --save react-moment npm install --save moment-timezone after that in my client folder
21. After a new try to start this error showed up Module not found: Can't resolve 'react-select' in ...
22. I used npm i react-select to fix that

Now I am gettig errors over and over again, so I want to ask you if anyone could tell me, how I can set this up correctly, because how I already said, I am new to react.