Those are for Nintendo 3DS, not DS. 3DS emulators like Citra support .3ds, .cia, and sometimes .cci files—but that’s a separate topic.
Sometimes archives are nested (archives inside archives). 7z to nds converter
Before diving into the "how," you must understand the "why." Many beginners mistakenly believe a 7z file is a video game. It is not. Those are for Nintendo 3DS, not DS
7z2nds input.7z --output game.nds --trim --patch translate.xdelta
If the emulator crashes immediately upon loading the .nds file, the original archive might have been corrupted during download. Try re-downloading the 7z file and extracting it again. Sometimes archives are nested (archives inside archives)