These are complex words. Sole has two unrelated meanings. And soul, while it has one main meaning, is rich and subtle with ideas specific to Western culture.
Sole can be a noun meaning "the under-surface of a foot" or "the inside bottom of a shoe (or other footwear)" or an adjective meaning "only" or "alone":
I hurt the soles of my feet because there are holes in the soles of my shoes!
A sole hiker should always tell someone where they are, for safety.
Soul is primarily a noun meaning "the most essential non-physical part of a person" or "the depth and power of a person’s spirit," or an adjective related to a popular style of American music:
The music I play comes from the depths of my soul. (non-physical part of a person)
She sang with such soul, that every listener was moved to tears. (emotion and spirit)
Soul music evolved from a combination of blues, jazz, gospel, and rock music.
Soul is a very big concept in America with deep roots in African-American culture. A person who has soul, expresses strong feelings openly, which is highly valued in traditional African-American culture, which seems different from many European and Asian cultures. If you want to know what soul music is listen to something by The Supremes, Marvin Gaye, or Allen Toussaint, perhaps.