iPhoto

No you cannot run iPhoto but you certainly can run Photos, the app that replaced it, and this can open and migrate your iPhoto Library.

Hold down the option (or alt) key and launch Photos. From the resulting menu select 'Choose Library' and point at your iPhoto Library. It will do the rest.

No. iPhoto was dropped and replaced by Photos many upgrades ago. It cannot run on Catalina or Mojave nor any version after El Capitan, I believe.