What would be the Hebrew for seeker of light or seeker of God or something that means One who is seeking to know the light or One who is seeking to know God?

Answer 1

You can say that in many ways, but it will depend on if the "seeker" is male or female:

• [Male] Seeker of light = mevakesh or (מבקש אור)
  
• [Female] Seeker of light = mevakeshet or (מבקשת אור)
  
• [Male] Seeker of God = mevakesh elohim (מבקש אלוקים)
  
• [Female] Seeker of God = mevakeshet elohim (מבקשת אלוקים)
  

Answer 2

a male truth seeker = mechapes emet (מחפש אמת)

a female truth seeker = mechapeset emet (מחפשת אמת)

Answer 3

male seeker of the truth = (mechapes ha emet) מחפש האמתfemale seeker of the truth = (mechapeset ha emet) מחפשת האמת