Sure, what size are you in men's clothing? IF you are really large you may need to go to larger women's clothing.
There are basically 3 types, Junior, Miss and Womens.
Junior is usually for younger (or older) slender girls/women, (little to no hips or curves). Sizes run odd, 3, 5, 7, 9, 11, etc. (Think Carmen Diaz, Penelope Cruz size.)
Misses is for women who have developed jips and breasts, not too large. Sizes run even 4, 6, 8, 10, 12,14,16,18.
Womens is for extra large women. Large in everyway, hips, stomach, breasts etc. Not sure what they run, but probably start at 14, 16, 18, 20, 22, 24. I have always seen XL, XXL, XXXL and so on.
Those are your basics. Now depending on your size, and the type of clothing, dress, pant, top, etc., like me I can wear a Junior 10 or a Missy 8.
(You can look at my recent images, I am 8 or 10 depending on brand and quality. https://www.zity.biz/index.php?mx=gallery;ox=showalbum;ax=6662 )
I never stick to trying on only one size because of styles and manufacturers have "their true 8" which is just a little different than another manufacturer.
So I can wear an 8 in an expensive cloth, a 10 in a less expensive item.
As far as shoes, go to a TJMaxx or Ross and put you foot next to the largest size. Gage from there.