Unfortunately, on PS4, mods are more limited - Bethesda says that PS4 mods will not be able to use “ external assets,” which is a bummer. It’s also worth noting that, depending on what platform you are playing on, your options will greatly differ. Do note that if you have mods active, your save file will disable achievements and trophies.
It’s literally just a matter of selecting your preferred mod, and downloading it.