>>528196239
>>528198040
I found these tutorials pretty helpful for myself to add armor and other items to a follower:
https://wiki.nexusmods.com/index.php/Creating_a_custom_race_for_Skyrim
https://wiki.nexusmods.com/index.php/Creating_an_armour_for_Skyrim._Part_2#Add_the_armour_to_the_game_using_the_CK