You will have to correct for the purity of your sourced citric acid. But to create any solution, determine your desired concentration first.
I want 50% CA solution. Let's say 50g CA/100mL solution so that it's 50% CA by weight/weight. (I don't know if you can make this strong of a solution using water or not, this is just an example).
The table linked has pre-made conversions from g to volume to correct for the volume change from adding CA, since you can't just add 50g CA to 100mL DI water without changing the final volume.
Get an accurate container (graduated cylinder or accurate graduated flask)
Add 50g CA to container
Add DI water in small amounts, swirling to suspend/dissolve the CA as you go (e.g. add 30mL initially then 5 mL at a time)
Continue to add DI water until your final volume is 100mL. You now have a solution that contains 50g CA/100mL of the solution you made. You can convert that to molarity, concentration, whatever.
Once you have this concentrated solution, you can make further dilutions using this equation:
C1=Concentration of solution 1
V1=Initial volume of solution 1
C2=Concentration of new solution
V2=Volume of new solution
Solve for whatever variable you want.