man or human?

It’s really difficult for me to understand the usage of the words “man” and “human.” I would always use the word “human” instead of “man,” after all it invelves both “man” and woman.” However, I think “human” is much lesser used than “man,” or not? E.g. I would say “the human of today,” or “the human of future” – meaning a general person living nowadays or in the future. Or I would say something like this: “The(?) human has the ability of planning different things.” Or: “There is an unknown being of the human, which is…” (Maybe the right choice is “one” in the latter case, I don’t know.) I can’t judge if these can be considered some kind of comparisons with animals – as far as I know, “human” should be used only in such cases, but suppose no word is said about animals.