AetherSX2 supports .iso, .bin, and .chd file formats. You can load games from your internal storage or an SD card. Navigate to the "Game List" tab in the app, select "Add Game Directory," and point the app to the folder containing your PS2 ISOs.
When you search for "aethersx2 32 bits android full", you may stumble upon pre-configured "ROM packs" or "BIOS bundles". Do not download those.
Emulation is a preservation tool. The 32-bit AetherSX2 exists so that people can replay their childhood PS2 games on a device they already own—not to bypass game purchases.
Unfortunately, the future is bleak. No active developer is maintaining a 32-bit PS2 emulator. The official AetherSX2 is dead, and newer alternatives like Play! and DamonPS2 are either incomplete or malware-ridden.
The "full" 32-bit build you find today will likely be the last functional version forever. As Android 14+ drops 32-bit library support entirely, even ARMv7 devices will become obsolete.