Naive

adjective
marked by or showing unaffected simplicity and lack of guile or worldly experience
“a teenager's naive ignorance of life”
Similar: naif
adjective
of or created by one without formal training; simple or naive in style
“primitive art such as that by Grandma Moses is often colorful and striking”
Similar: primitive
adjective
not initiated; deficient in relevant experience
“it seemed a bizarre ceremony to uninitiated western eyes”
Similar: uninitiate, uninitiated
adjective
lacking information or instruction
“lamentably unenlightened as to the laws”
Similar: uninstructed, unenlightened