I agree on the skipping on the injection, especially if this is your first brisket.
Learn what you've got and then you'll determine how to build on it (if it's even necessary).
I've not cooked on a UDS but fat down seems more logical.
Lonestar 24" Vertical offset w/ Insulated Firebox & Performer Platinum
Former owner: Jambo Backyard, Klose BYC, Med. Spicewine, Pitts & Spitts, XL & (2) Med. BGE's, 22" WSM & (2) 18" WSM's, 18" & 22" Weber Kettles