Protons have a positive charge.
How I remember is Protons and Positive both start with the letter P.
What is your question about it?
To calculate this, we need the Molarity formula. This formula tell us that Molarity, which is a concentration unit, is equal to the number of moles divided by the volume. In this question we already have the Molarity and the Volume, so let's build our equation:
C = n/V (You can see Molarity with the letter "C" because it means concentration)
3 = n/1
n = 1 * 3
n = 3 moles of NaOH