Case 1-1: Big News
Case 1-1 is just the cutscene that you get after you give Katey here first dose of Zombrex at 7. I suggest you try to stay on the clock, since it's good to burn through the story mission quickly and get right into the other day 1 rescues.
Case 1-2: Alive at the Scene
This is your first story mission in Dead Rising 2 and the first mission after you get Katey’s first Zombrex. You need to find the reporter spreading the false story about Chuck and hopefully find the source of the outbreak. This means a fairly standard run out onto the Platinum Strip and into the Fortune City Hotel.
For this one, you will probably want to go ahead and pick up some survivors. You’ll run right into LaShawndra on your way out of the Safe Room and you can find her husband, Gordon, hiding in the Casual Gals store just a few feet away.
Give Gordon a knife or something basic so that he can defend himself and then follow the arrows out onto the Platinum Strip. Go ahead and pick up Doris and Chad for “Lost.” Walk to the right, toward the arena. You’ll run right into Chad. He’s running around Juggz firing a shotgun, so he’s easy to spot. Talk to him and add him to your group. Doris will be on one of the Souvenir stalls firing at the zombies. Get close and wait for her to climb down and reunite with Chad. After their little reunion, you can talk to her and add her to the group. Chad’s a menace with his shotgun and will probably do about as much harm as good (he is great at busting holes in hordes, he just tends to blast the other survivors a lot too). Doris is pretty useful though and LeShawndra and Gordon should have enough health to survive and help you cut through the hordes.
Walk over to the Fortune City Hotel with your little army to meet Rebecca. Talk to Rebecca to start off Case 1-3: Insecurity.
Case 1-3: Insecurity
This is basically just a mission to follow Rebecca. If you stick close to her, you will be fine. Your survivors (if you brought any) should be fine and able to help clear out the hordes, as long as you keep pushing them forward and keep them from engaging any large groups. For the most part, this is your lesson that you need to avoid hordes. If you don’t have access to any combo weapons yet, then you just won’t be able to safely fight your way through the horde. There are a few chainsaws along the path, but those are a bit of a pain to use and have very nasty friendly fire. There are plenty of lead pipes and boards lying around, so you should be fine for weapons. If you want, you can also grab a utility cart and use it to crash through the hordes. The focus is on clearing a path through, not clearing the South Plaza.
Rebecca should make it to the Arena entrance after a little run. Stick to the edges of the horde at the center of the Arena entrance and get into the security room. Open the door to get the cutscene and officially end the mission and bring up Case 1-4: Alliance.
Case 1-4: Alliance
There’s nothing to this one. If you get a new survivor message (I got Short Sighted, for example), then consider adding them to your group. Otherwise just work your way back to the Safe Room at the Royal Flush Plaza. Note that you shouldn’t follow the guide arrow for this one. I found it much easier to just go right out the main entrance for the arena and back onto the Platinum Strip. It’s easier to dodge the zombies in the open area.
The mission will end when you get to the Safe Room and enter the Security Office inside.