It is not clear what your question is.
If you want to know how to plot a function, populate two columns in a
worksheet; one containing x values and one containing f(x) values.
Select both columns, and Insert|Chart.
If you want to know how to get the pdf and cdf, it depends on what
distribution you want. Some distributions (such as NORMDIST, GAMMADIST,
and EXPONDIST) allow you to select either the pdf or the cdf with a
parameter. Other distributions only give the cdf (such as BETADIST) or
one minus the cdf (such as CHIDIST and FDIST). For the pdf in that
instance, you will either need to look in a textbook for the formula, or
write an algorith to numerically take the derivative of the ...DIST
function (Excel has no general purpose calculus routines built in).
Jerry
