So,I really wanted to update my game,but I can only find the newest patch.I need the oldest to the newest.Can someone give me a link?

The latest 1.2.416 patch is cumulative, it is the only patch you need.

You can get it at Tesnexus - http://www.tesnexus.com/downloads/file.php?id=11364, Just make sure you get the proper patch for your version of Oblivion.

You may think I'm dumb for this,but,How do I know which version is my Oblivion?.I already tryed the UK,but it said:Old files not found.

How to find out which region your Oblivion game is from? I don't know.
You can find out which version number you already have your game patched to by looking at the numbers displayed at one of the bottom corners of your screen at Oblivion's title menu screen when you load the game.

Your region is generally the country where you bought the game and if the game was a retail version or digital version (Direct to Drive) and whether or not you have Shivering Isles as well.

I am assuming you tried the retail UK updater version, try the retail US version. If you have the Direct to Drive version get the Direct to Drive version patch. And make sure if you have the Shivering Isles that you get an updater that has Shivering Isles in the title.

I need Shivering Isles to update it?Also,I live in Brazil,so what version I must download?

No you get the Shivering Isles update version if you have the Shivering Isles. And I do not know what version you get for Brazil sorry.