How do I know wether to do up bow or down bow on violin sheet music?

The are marks above every note in the beginning of each measure, there is a different sign above the note that indicates up, and another that indicates down. Either look up or ask your teacher which sign means what. Hope this helps!

Explanation:

earliest

neumes above text

neumes

colored lines

neumes

4-line staff

f, c, or g clef

notes on 5-line staff with clef

mensuration (longas and breves)

time signature (perfect or half circle)

most recent

notes on 5-line staff

modern clefs

modern note values (whole, half, quarter, and so on)

modern time signature

italian words and abbreviations for dynamics and tempo

staccato, slurs, and so on