High effort. Because Bethesda frequently updates the game to add Creation Club content, SKSE and any dependent .dll mods often "break," requiring users to either update the tool or roll back their game version.
If you tell me , I can write the code or guide you through the setup. Skyrim Script Extender (SKSE) | Modding.wiki skse 16342
Go to the archived SKSE builds or the Nexus Mods page. You are looking for skse64_2_01_02.7z . High effort
Do not install SKSE into your "Data" folder. It must go into the root directory where the game executable lives. : Steam\steamapps\common\Skyrim Special Edition\ skse 16342