how to have 2 main branches in git code example

Example 1: git new branch

$ git checkout -b [your_branch_name]
# Switched to a new branch [your_branch_name]

# This is shorthand for:
$ git branch [your_branch_name]
$ git checkout [your_branch_name]

Example 2: git merge branch to master

$ git checkout master
Switched to branch 'master'
$ git merge iss53
Merge made by the 'recursive' strategy.
index.html |    1 +
1 file changed, 1 insertion(+)