“Hiking” is like any other kind of outdoor activity: it can range from a literal walk in the park to scaling a mountain. You’re describing hiking the same way someone who wants to get into swimming might describe preparing to cross the English Channel; if you want to get into swimming, start with a shallow indoor pool and then if you feel like it, work your way up from there.

I will say that there is a lot of misleading hiking info on the web (as in, maps of trails that are inaccurate, don’t exist, or that go through private property); I’d recommend finding a book (as in, made of paper) of local hikes from your library or bookstore (if you live in an area with an outdoor store like REI that’s a great resource). Select an “easy” hike of 1-2 miles from the book, ideally a “popular” hike (as in, one that’s likely to have a lot of other people on it) that’s somewhere within a short transportation distance, and do that for your first hike. Short, easy hikes don’t require anything more than comfortable footwear, and maybe a water bottle if it’s a hot day. Until you start getting into very long, very remote, and/or technically difficult hikes, assuming you’re in decent health there’s really very little to hiking other than stay on the trail, keep an eye on the weather, and don’t push yourself beyond your limits… or more generally, “if in doubt turn around.” I do recommend getting an Open Street Map app for your phone, as it’s generally more accurate than Google Maps; some trails are marked better than others, and OSM is a good backup to have in your pocket if you get lost or turned around, although it’s mostly only necessary if you’re going into an area that has a lot of intersecting trails.