Do Epithelial cell abnormality and ASC-US require a surgery? And why? Or what's the best solution for it because of the huge amount of discharge?

No surgery needed. Most ACS-US which very often are due to a transient viral infection (HPV or others...) will require no treatment at all and will resolve spontaneously over 6 to 12 months particularly in young women like you. The discharge may require further testing to determine its cause and hopefully its treatment . It too may disappear with simple hygienic measures and some patience.
Recheck soon. Usually ASCUS is re-evaluated in 12 months by your physician however the cause of the discharge should be evaluated even sooner if still problematic for you. .