So i havent played the first one. If i want to get Dead Rising 2 should i play the first one first? OR shouldnt i get either one? I hear a lot of mixed things about both games so im not sure if its worth to get. However it seems a lot of fun to just kill zombies like that in a game instead of a LFD type of killing zombies.

Get it. Take a dive, try something new.

i'd rent it, or barrow it, if you can. i bought it, i love it, depite it being a rocky relationship, but enough people have enough legitimate complaints about it that i say you shouldn't spend full price just to find out it's not yer thing.
you just have to approach the game with the right mentality and the understanding that some of the side missions you're going to have to let expire/fail your first time around...you can then blow through the game for a second playthrough and see all the sites.

Yes. There isn't really any other game quite like it. It's a pretty unique experience, and I think it's pretty awesome. Get DR2 first; it improves almost every aspect of the original, and the result is a significantly better game.

Yes, but you spend the first playthrough just messing around killing zombies and leveling up. I went straight for the story/side missions and I was always pressed for time and in a rush. It kind of killed most of the enjoyment for me. 

Yes.  Yes yes yes.  Yes,  YES.  Yes? 
 
Yes.