When you find a "save game download" online, it is usually provided as a file (Registry file) or a folder of .sav files. If it's a .reg file:

Once you have downloaded your desired .sav or folder, you need to place it in the correct directory for the game to recognize it.

While known for Skyrim and Fallout mods, Nexus has a small but growing Streamer Life Simulator section. Users upload saves and mods with virus scans.

The save path is usually: C:\Users\[YourUserName]\Documents\My Games\Streamer Life Simulator\Saves\