1. NaOH + HA --> NaA + H2O
Do you think the above equation can answer your question?
2. Just take an average on your titration results (no. of citric acid added for reaching the end pt if methyl orange is used, color will change from orange to yellow. if phenolphthalein is used as indicator, color will change from purple (deep pink) to colorless)
3. In normal cases, you no need to dilute as citric acid is weak acid and NaOH is strong base. The steapest proportion on titration curve lies near above 7, so phenolphthalein is a best indicator to be used.