You'll generally run git status to get an overview of the index and working tree of a git project. This is a porcelain command meant for a Git end-user. If you want to do some scripting, you'll want a plumbing command like ls_files.
The git ls-files command will
Show information about files in the index and the working tree
This command can be used to list all untracked files in the working tree with two flags.
The --others flag will show untracked files in the output
The --exclude-standard will use the standard ignore files like .gitignore and .git/info/exclude.