Complete noooob :[

I'm trying to get NES and SNES on my PSP but it says its corrupted or it won't run...
I downloaded some PSP Brew stuff but idk how to make it work...
I haven't looked at any tutorials becuase I don't know what to look at.. (sorry)
I have an old psp probaboly the oldest one! please help!

Go to Settings and find out what version (firmware) your PSP is under? That could be the issue. Now don't upgrade.. just tells us so we can point you to the right direction!!

System Software Version 3.52?

I have a feeling you are using a legit firmware from Sony and not a custom firmware in order to play homebrew games. What you need to do is downgrade to 1.50 and then proceed in getting a custom firmware to get you back on 3.52 or newer and play hombrew. For that, you will need to ask someone else to learn how to downgrade to 1.50, since I am not sure if it's still possible to downgrade from a legit 3.52 firmware? What I do recall is that you can only downgrade from a 3.50 firmware so you may be out of luck for now until they crack this for you. Here are more details about the 3.50 to 1.50 downgrader (which doesn't apply to you): http://www.psp-hacks.com/file/1181

Now then, only one final question: Is this a fat PSP or a slim PSP?

And also this guide might help you get on track with what you need in order to play homebrew and more: http://www.psp-hacks.com/forums/viewtopic.php?id=119276

I just upgraded it today too :/ Before realizing I could put roms on it..
Its a psp fat btw.

Hey! I just took my own advice and started to read that guide I linked you above. And started to read more about the Pandora Battery trick. Turns out that by having this battery, you can downgrade any firmware to 1.50!! Also it helps if you ever happen to brick your PSP. It seems that this technology is used when you send your PSP for repairs to Sony and the utilize this special battery to fix your PSP.

In the guide above, it shows you links on how to create your own Pandora battery, but if you have issues doing it, you can also purchase one for the fat PSP (click here) http://www.consoleshop.com/product.php?productid=17108

Also, there is a different one made just for the slim. click here: http://www.consoleshop.com/product.php?productid=17184

I think I am gonna get one.. you never know if you need it. I just hope that Sony doesn't later introduce a new firmware that will disable the functionality of a Pandora Battery.

[DarkPacMan77]

Yep, Pandora's Battery can return any firmware to version 1.50. From there, you can install a custom firmware and then you'll be playing NES and SNES and all of that good stuff in no time

-DarkPacMan77-

So after I get that... where do I get custom firmware?
And idea whats the best?
And does N64 run good on PSP?

A few games run fairly well on psp:
Starfox 64
Super Mario 64
Mario Kart 64
Super Smash Bros.
Maybe others, but I know those off the top of my head.

All the old school emulators run fine? (Nes, Snes, mame, etc.)

NES and MAME do, but the SNES has some slowdown issues.

Can anyone link me to some custom firmware?

There are some tutorials in the tutorial section with the downloads and how to install them. Also check the 'Releases' part of the 'Emulators, Applications, and Games' section for released cfw.
Or you can check the download section for cfw.