I come across concrete sealers are super straightforward to use. Just clean up the concrete, let it dry, then use the sealer by using a mop. It won’t alter the coloration from the concrete, but will darken it a tiny bit and include some gloss. You’ll need to reapply it https://mcgepoxycoatings.com/epoxy-vs-untreated-concrete-garage-flooring-which-one-is-best/