ask a docent (a guide who knows about the museum and its exhibitions) for a tour
encourage taking your art journal to make notes about things of interest to you - works of art, history, collections you like, etc.
if taking notes in your art journal, do so in pencil, pen inks can leave accidental marks that can damage art (just look at how many times an ink pen has marked up your purse or a pocket) and a docent may come and scold you.
don't drink, snack or have candy/gum
travel light through a museum, don't do big and bulky
though artwork is beautiful and you might be amazed that something is really a painting don't reach out to touch artwork.
no flash photography is sometimes allowed but if it is it's only of their permanent collection and for personal use (not published or internet use)