Anyone can help me?

[LunaMoo]

"ISO" just happens to be a popular and rather simple container for disc dumps, you can make an ISO from any disc or even directory on hdd as well as flashdrive ~ it really doesn't say anything about "format" the data stored on it uses nor platform it was designed to run on, and PPSSPP will only be able to run PSP games, hence showing error on iso made from ps2 disc.

For ps2 emulation check PCSX2 and Play! as those are the only existing ps2 emulators.

As for Gold version of PPSSPP - it doesn't differ from regular version aside from the color. You can think about it as a form of donation as PPSSPP is open source anyway.