If i can insert my finger into my vagina hole, does that mean my hymen is big enough for sex and i don't need hymen surgery?

Yes: Though you are unlikely to need surgery on your hymen even if you could not. It can break easily with intercourse, though often it breaks on its own long before your first intercourse.

Rarely needed: Most hymens are thin and break easily with first intercourse. If yours is thick tissue, a finger width hole may not mean yours can break easily. If this issue bothers you a visit with your doc may be in order. Or discuss this with your partner. A sex toy with realistic dimensions could be advanced through the hole to see if it begins to tear. If it is too tough, the surgery may be needed.