There's a couple of good ways to do this with functions. The simplest is
to
put the formula =TODAY() in the cell, and then format the cell for any
date
format you like (I'm thinking the one that says the month name and the
year).
Unfortunately, there is no format which only says the month name, and
nothing else.
The other way, which is slightly more complex, is to use a combination of
the Today, Month, and Choose functions as follows:
=CHOOSE(MONTH(TODAY()), "January", "February", ..... "December")
This will give you just the current month, as text.
Or, you could do this...

=TEXT(TODAY(),"mmmm")

(or use "mmm" for the abbreviated month name)

Rick