Should I use GitHub, a local Git client, or another remote host?

Git and GitHub are separate things. Git is the version-control system that can run entirely on your computer, while GitHub is a remote hosting service built around Git. A local GUI gives you commits, branches, history, worktrees, and conflict management, but it does not replace the benefits of a remote repository. Remote hosting provides an off-site backup, lets you work from multiple machines, makes sharing easier, and gives you experience with tools commonly used in industry. Keeping everything on one hard drive is risky because a drive failure could erase both your project and its history.

The reliability concerns are probably being overstated for your situation. GitHub is generally dependable for ordinary repositories, and many reported problems involve optional services such as automated workflows rather than basic source hosting. If you are uncomfortable with it, alternatives are available, but there is no technical need to abandon remote hosting entirely. A sensible setup would be local Git plus a remote repository, with another backup if the projects matter to you.

For learning, spend some time with the Git command line even if you ultimately use a GUI. GUIs can make common operations convenient, but understanding commands such as status, add, commit, log, branch, switch, merge, pull, and push will make it much easier to troubleshoot and follow documentation. A GUI is an interface choice, not a replacement for having a remote backup.

You don't have to choose between local Git and a hosted service. Use Git locally with whichever interface you prefer, then push the repositories to GitHub, GitLab, Codeberg, Bitbucket, or a self-hosted service such as Gitea or Forgejo. If you dislike GitHub's policies or features, switching hosts is straightforward because they all use Git underneath. Just make sure anything you push does not contain passwords, API keys, or other secrets.