@ben-coyle2 This is just git doing its thing:
You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by switching back to a branch.
Here's a link to free online version of Pro Git for those who may want/need more help with git.
You should not try accessing site with "this running". Having switched to a different branch/version of NodeBB, you now need to build/setup that branch. I am unsure whether you need to re-run the "setup" target or just "build" target, as I am still on 12.x and ignorant of whether any config.json knobs changed 'twixt the two versions. Probably does not hurt to run setup again. Do this as your nodebb user, not root, btw.