The key ingredient in making soap is sodium hydroxide / NaOH / lye. It is incredibly caustic and will burn any natural ingredient that's added. There are ways around that (hot process soaping). For a new soapmaker, I highly suggest making a lot of simple recipes to nail the hot process and cold process. Simple means only oils, lye, and (if desired) essential oil for aroma.I've been curious about making soap aswell.
During late spring we have loads of spruce and pine shoots on the trees here, would they be good to use in soap? I've heard they have some compound in them that is mildly antibacterial.
And from midsummer and forward the skvattram is ready, I think they are called wild rosemary or labrador tea in English, no special properties but they smell godly.
Good white soap can be made out of stuff you buy at walmart and home depot. Coconut oil, lard, lye (drain cleaner). Even the essential oils can be picked up locally (pine, lavender, lemon grass). No special equipment is necessary, but for hot process soap a small crock pot is ideal. Also, you'll need some sort of mold. I made one out of wood that I lined with parchment paper, but the following works great and is cheap.
https://a.co/d/dFIZFOh