Welcome to PSP3D there is only really two ways of running homebrew on
a 2.5, the first is the gta gamesave hack (which offers about 5 games).
But you really need the eloader which can run a huge amount of eboots.
Go here to download the eloader.
btw you will need gta lcs for this to work because the eloader is based off the gta gamesave hack