In this guide I am going to upload my existing project from my linux machine's terminal to github.

Initiate Git

Open terminal and navigate to your project's directory.

git init

Configure your username and email

git config --global user.name "your_github_username"
git config --global user.email "your_github_email"
git config -l

Create an empty repository on Github

Copy the https link of that repository

Add remote origin

git remote add origin https://github.com/username/repo-name.git

Add all files into stage and commit with commit message

git add .
git commit -m "Initial Commit"

Now push to github

git push origin master

Generate Access Token

Before entering your password Go to Settings > Developer settings > Personal access tokens > Tokens (Classic) > Generate new token (classic) > Mark repo and add a note > Hit Generate Token > Copy the Token

Paste your token into password

Cache the record locally to remember the token:

git config --global credential.helper cache

Verify

git pull -v

Source: StackOverflow