what do you mean by stepping here? to give just one step as opposed to several continuous steps over a short distance, i.e., walking? skipping maybe?
I think the Hungarian sentence doesn't make more sense than the English one... "lép" means the same as "step".
So, assuming the sentence makes more sense in the context of a conversation ... in English, this might mean something like stepping from rock to rock across a stream, or stepping carefully through an area with obstacles ... something like that.
Does the Hungarian version also imply something like this?
I don't think it would work in Hungarian. "lép" means taking one step or a certain number of steps, it doesn't fit in a sentence with "sétál". If someone is stepping carefully for a while, you should rather say "lépked" or "lépeget" (frequentative form). "Nem sétálok, hanem lépegetek." sounds better but still quite far-fetched.
Take three steps. Ok now walk. Steps are individual, usually carefully placed motion. Walk can be saunter, meander, etc. The individual "steps" are not important.
Please DO correct me if I'm wrong, but I'm starting to feel that:
• lép = walk (I know it's step, but it mostly just turns the English sentences into nonsense)
• sétál = take a walk, stroll