I had to look up your floor plan to see where your washer/dryer closet was located. Looks like you will need the 90* exhaust for the dryer. I have read here that some folks use a stud finder to locate the aluminum studs, and some use a tiny drill bit to locate studs. There has been lots of threads on installing washer/dryer. Try the search feature above.
MikenDebbie Aggie ‘77 in the sticks near Austin TX
2019 Chevy 3500 High Country DRW
2018 Montana 3921FB
Aussie Gus + Texas Heeler Jimmy