I downloaded a mod prides of skyrim. Once ive downloaded a mod how do i adjust its settings if it has difficulty settings? My nexus mods have sn option right in the game menu

Check the mod's documentation - the author should include instructions on how to adjust difficulty if this feature is included. In the case of Prides of Skyrim, difficulty is selected by which file you download; the first file gives you level-scaled lions and is easier, while the second file gives you high-level lions that are static-leveled and is much harder. Pick the one you want to use and install it; don't install both or you'll get conflicts.