Hello, I'm a begginer, I don't know really much on electronic and I want to make a portable ps2. Is it difficult ?
My only experience is making phobGCC and boxx style controllers with rasberry pico.
To do well? Yes. The PS2 can be an intermediate level console to portablise depending on how small you want to make it. There aren't a whole lot of readily available custom PCBs and open source case designs for it like there are for the Wii, but several beginners have created functional portables with a lot of study and work.
Check out the worklogs in the Sony section to see what other users have done before in terms of design, part selection, and troubleshooting. And give the videos in the Electronics 101 thread a watch https://bitbuilt.net/forums/index.php?threads/electronics-101-videos.1224/ . There's no step by step guide for a project like this, but you can follow what other people have done and ask questions when you need to.