Your question seems somewhat unclear.

(BTW, a nautical "map" is properly called a "chart").

To plot latitude and longitude, you will need a chart (or a map) with
scales and reference points for latitude and longitude. A pair of
dividers (geometry compass will substitute), will be essential, along
with a straight edge and a pencil.

Latitude and longitude are expressed in degrees, minutes, and seconds.

Lines of latitude run parallel to the equator. (think of them like
rungs on a "latter"). Lines of longitude run betwen the north and south
poles. (it's cold at the poles, so you need your "long" underwear)

In a practical application: let's say you wanted to plot the
coordinates 47.31.1N and 122.28.5W. You could do that by using chart
#18448, but taking the same steps would help you find a different plot
on any chart where different coordinates would appear.

To start, you need to establish either your latitude or your longitude.
Some purist might insist that it's important to start with one position
or the other, but I usually start with latitude.

On chart 18448, there's a line of latitude marked at 47 degrees, 30
minutes. Since we're looking for 47.31.1, that line is a good place to
start. On the left edge of the chart is a scale to use when calculating
latitude. Take the dividers, (or the geometry compass), and spread the
legs until one is on the 47.30 mark and the other is
11 little tick marks to the north. The first ten tick marks
bring yhou to 47.31N, and the 11th brings you to 47.31.1N

(incidentally) that minute of latitude between 47.30N and 47.31N equals
a nautical mile.

That spacing on the dividers can now be used to establish 47.31.1
anywhere across the chart, simply put the "bottom" leg on 47.30 and the
more northerly leg will be on 47.31.1N (as long as it is at right
angles to the line)

At this point you could mark any two points that are 47.31.1N on the
chart and draw a line between them. Somewhere on that line, or on its
extension beyond the reference points, is where you are in relationship
to the equator. To find out where you are on the globe, you need to
find the single point on that line that represents your position.

At the top of the chart is a scale that represents longitude. In this
example, we are looking for 122.28.5W

On chart 18448, there is a vertical reference line for 122 degrees, 30
minutes W. Using the dividers again, measure toward the prime meridian
in Greenwich Englan (to the east) 11 and 1/2 tick marks. We measure
east because we are looking for a longitude with a lower number than
the reference line, and we'd measure west if we wanted a longitude with
a higher number, (for example, 122.31 would be left, or west, of
122.30).

The dividers will now indicate 122.28.5W anywhere on the chart as long
as one leg is resting on the reference line and the other leg is at
right angles to the line.

When you find the point where the line of your longitudinal position in
relationship to the prime meridian intersects the line of your lateral
positional in relationship to the equator, you will know just exactly
where you are on the chart and will have "plotted" your position. (In
this case, you would be just off of Pt. Vashon, at the north end of
Colvos Passage, in Puget Sound.)

If that doesn't help, or answer your question, please try restating the
problem you are experiencing.