How do I properly upload a localhost website online?

I have a ReactJS project for my Front and a NodeJS project/server for my back. My Front depends on my Back because for example in the Login part, I ask the server if the user is already in our database.

To execute my project, I just open 2 terminals and do npm start in each Front and Back.

I know that in order to upload a website with a personal domain name, I should:

1. Buy a domain name
2. Pay a subscription to a web-hosting website like GoDaddy, Bluehost, Hostgator etc.

If I pay a subscription to some web-hosting website, will I be able to put my Front AND Back? I have seen some tutorials online and people just make a simple HTML/CSS/JS website and upload it. I never see anyone uploading their own Server and making requests to it. What should I do?