openings for beginners
You are better off starting with "opening principles" as they are foundational to all chess openings: https://www.chess.com/blog/KeSetoKaiba/opening-principles-again
When you do eventually decide to stick with one (ideally mainline) opening, then I recommend getting an opening book on that particular opening or an opening course on that particular opening. You can also search the same on YouTube if you find someone who teaches this opening, but books and courses tend to have the advantage of more repertoire based planning in case the opponent doesn't play exactly as you expect.