I  was so amazed when I started making bread of the many types of flour that are available.

 All Purpose flour is used for most things but for bread you need higher gluten, hence Bread flour. If you can;t find bread flour in the grocery stores order it online. Bread flour is a white flour. If you make rye bread you use part rye flour and add white bread flour. The same goes for whole wheat flour.

Semolina flour is mixed half & half with all purpose flour for making pasta   but you don't need semolina to make pasta. A.P. flour is fine.  In fact, fettucine noodles are lighter and absolutely delicious when made homemade.   Store bought fettucine seems heavier and takes longer to cook. My stash of flours consist of All purpose flour, bread flour, rye, whole wheat,buckwheat (for pancakes & waffles) and semolina. Once in a blue moon I'll buy cake flour which is finer and silkier.

       Think of all the things you can make with flour: 

          Pastas(spaghetti, ravioli,lasagna,noodles for soups & stews,fettucine,) tortillas , pierogis, breads, bread crumbs from stale bread , cakes, pies,struedles and other coffee cakes,cookies, biscuits, dumplings,pancakes,waffles. There's more but I can't think of them now. So, unless you have dietary restrictions flours are a good thing to stock up on. It takes time to do that. We would buy a bag or two every time we grocery shopped until we had enough.
           Rice, barley, dried beans , lentils and peas are good to store up  also, I get gallon pickle jars and hot pepper jars from the mom & pop deli nearby. Flour and beans, etc store beautifully in them and so far I haven't had bugs make their way into those jars. Melted wax around the rim of the jar lid is an extra precaution to make a snug fit,