Tips for a newbie please

So I just got a 360 last Friday, along with FFXIII. Thing is I decided to finally start playing (been playing Tekken 6 ALOT) today;(as I'm typing this I'm sitting in front of the title screen).
Which brings me to why I'm posting this;I do not want to make the same mistakes I did with past FFs (mainly missing stuff or not fully understanding something that ended up causing problems later). So, is there anything I should know or keep in mind before I start playing? Any help/tips will be greatly appreciated. :)

In 13 I greatly suggest not running from any battles you encounter, you'll need all the experience you can get your hands on considering how linear the game is for the first 30-ish hours. Also practice with the paradigm shifts and their various combinations, it will serve you more than almost anything on that game.

Practice with your battle techniques, as TrollHunter said.

The game is pretty straight forward, so just make sure you explore off the main path whenever possible to find treasure and such. And when you arrive at a new area, turn around first and check behind you. There's stuff hiding back there sometimes!

Enjoy it is probably the last point. A lot of this game is different and sometimes in a way you won't like, but just enjoy what you can :D

The game does a lot of handholding and forced tutorials. Once you get the freedom to set up the party and paradigms the way you like them, the game becomes a lot more fun.

In most of the game, you should only upgrade one weapon and accessory at a time. When doing the sidequests, you can explore other upgrades. Hold on to at least one copy of every unique item, since some items aren't replaceable.

Alright, thank you for the replies. I feel much more prepared. XIII feels so different :-/ but atleast it's fun (so far). Thanks again.

to be hones... i think u should just play, so you dont spoile the game for yourself with tips etc from here...
after that u should play it again, but than 'slower' so you get the full 100% out of it..

I know with Final Fantasy its not really reasonable.. becaus the game takes ages to get through (atleast i think so :) )

Pay close attention to the chain gauge as you fight, so you learn what things make it go fast, and what slows it down. Once you learn how to manipulate it the way you want to, battles become much easier!

One thing I always did during my first playthrough that I think made things harder for myself was I always had this obsessive compulsive thing to let my party leader's attack queue finish before switching paradigms even when I urgently needed to heal. Don't do this, because just wanting to wait a few seconds more to get a couple more attacks in may hurt you more than help you. Switch paradigms as soon as you need to. The battle also goes much faster when you shift during an animation.