The PlayStation Store on PSP closed March 31, 2016 (purchase) and July 2, 2021 (download list access briefly restored, then ended). You cannot buy or download games directly on the PSP anymore.
ISO folder).zRIF / rap files. Requires PSN Stuff / PKGj (homebrew storefront) on PSP..iso/.cso to ISO/ or .pbp (PS1) to GAME/.Best path in 2024: PPSSPP on a modern device. Legal if you dump your own UMDs. Preserves the library better than aging hardware.