Confused about MSN...

The DNP is a quite new degree. The people who are pushing the DNP degree want to make it the mandatory preparation for advanced practice nursing, but that hasn't happened yet -- at this point, that is still just a proposal. As of now, you can still become licensed as an NP with an MSN.

Also, you don't have to get an MSN plus specialty NP education. MSN degree programs offer different concentrations ( like "majors"), and an MSN with a concentration in FNP, PNP, etc., is all you need to get licensed. There are post-Master's certificate programs, but those are for people who already have an MSN with a concentration in something else but now (for example,) want to become NPs -- the post-Master's certificate allows you to skip the "core" MSN courses (that the person has already taken) and just take the specialty courses specific to that concentration.

To a large extent, the "career options" available with an MSN depend on what the concentration of your MSN is, and there are many available -- all four of the advanced practice roles (all the varieties of NP, CNS (also many options), CRNA, CNM), administration, education, nursing informatics, healthcare policy, CNL (also new), probably plenty of others I'm not thinking of at the moment ...