In American English, we use the /u/ vowel in some words by itself, and in other words, we use a glide together with the /u/ vowel (/ju/). Here are some of the most common words, sorted by which sounds they use.
/u/ ("oo")
do, due, new, knew, school, food,
room, soon, move, true, blue, moon,
too, two, into, noon
/ju/ ("you")
you, use, view, unit, music
beautiful, menu, value, useful, users
university, youth, communication,
continue, review, human, computer,
cute, argue, amuse