Minimum necessary to try

I've used an electric since literally the first time I tried shaving. It's what my dad and grandpa both used, so never even learned to use disposable/cartridge razors. And that's largely been fine; I'm blue collar and rarely shave more than once a week anyway. But as I age the shaver seems to irritate my neck more and more, to the point that lately I have a splotchy red throat all day even if I'm quite gentle about it.

I've heard safety razors are much less irritating, and coincidentally I recently came into posession of an Gillette from the 70s and a few new blades for free. I'd like to try it out, but obviously I don't have any of the accoutrements to go with it. I'm also on an extremely limited budget at present (between jobs), and can't justify spending money on items I'm not sure I'll use. Would slathering my face with the regular bar soap I already own be good enough for at least an initial test to let me know if this is for me, before ordering a half-dozen other products to go with it? Or is there more needed as a bare minimum to even get an idea?