I second the recommendation for Dreaming Spanish. If you need help with a plan, here’s one to get started with: Watch a video from this superbeginner playlist every day. You can watch on Youtube or you can sign up at their website for progress tracking, but watching on their site for free has some limitations.

You can get more info about how it works here or here. Now, they’ll tell you that studying any other way isn’t needed or is harmful. There’s reasons and probably some truth to that, but I’m always weary of Youtube video makers telling me all I need to do is watch their Youtube videos for 8000 hours.

The other starting point I’d recommend is Language Transfer. Their method is cool, and assumes no knowledge coming in. Imo, starting your learning here is a good supplement to the other videos I mentioned. So as plans go, I think you’d do well to listen to one of these lessons each day in addition to a Dreaming Spanish video.

After you’ve got a sense of it built up, do grab a beginner’s textbook and learn some grammar. Can’t rec any, since I just learned with whatever we had in grade school. But imo there’s value in it.

From dabbling in it, I’d say just go ahead and start anywhere, Duolingo even, whatever wets your toes. The plan can form as you’re going, you don’t need some massive study routine planned out before you start, as you generally need to change things up and change things to suit you better as you go anyway.

If you’re stuck for starting places, there’s Duolingo and DreamingInSpanish, and also maybe a Spanish book to also reinforce grammar concepts.