# the hand of the Lord is upon you

"The Lord will punish you"

# you will become blind

"God will make you blind" 

# You will not see the sun

"You will not even see the sun"

# for a while

"for a period of time" or "until the time appointed by God"

# there fell on Elymas a mist and darkness

"the eyes of Elymas became blurry and then dark" or "Elymas started seeing unclearly and then he could not see anything"

# he started going around

"Elymas wandered around" or "Elymas started feeling around and"