Are you going just to the Mall of America or other places around? What are you interested getting? Here is the website that can tell you their stores.
http://www.mallofamerica.com/
The four big anchor stores would be places to check out (Nordstroms, Bloomingdales, Macys, Sears). You can get some good bargains in the Marshalls and Nordstrom Rack on the upper floor, they are "clearance" stores, the latter for the Nordstrom department stores. Both have Plus-size sections/racks. My motto is pretty much the Marshalls motto: Never never pay full price. Both these stores require a bit more patience because of the endless racks, so don't go when you are tired and "shopped out". If you can, I would go to the Nordstrom Rack as soon as it opens (most stores open at 10) because later the lines for fitting room and checkout get long. (The mall itself opens earlier for mall walkers, and there are cafes open earlier also, so you can get there before 10 for a good parking spot and then wander around a bit to see things.)
In specialty plus-size stores they have Lane Bryant which I like mostly for bras really, there are often seasons when their clothes are just not my taste. Their bras are excellent. There might be a Torrid/Hot Topic which caters to teenagers; I tend to go to Banana Republic/Loft when I am buying work clothes, otherwise the Marshalls. BR/Loft tend not to have sizes above 16 in the stores unfortunately, you have to go on line.
The DSW Shoe store TOTALLY. Be sure to check the clearance room in the back where everything is marked 30-70% off depending on the sticker. Nordstrom Rack also has a good shoe selection.
ETA: I just saw your height! There is also a Tall girls' store, don't remember exactly what is is called. I don't know their size range is because I am too short to go in there.
They have an Apple store also, that is my "home" store when I am in the U.S., that or the one in Southdale Mall a few miles away in Edina.
And I never pass up the IKEA, which is not part of the mall but adjacent.
If you are going outside the mall there are some very good consignment stores in the Twin Cities area, I dropped a bunch of dress and work clothes off at one of the Turn Style chains the last time I was home. They rejected some of it as it wasn't high-end enough!