What is the ideal age to get married? Is it the same for men and women?

In my opinion, the ideal age for getting to get married is around 30. 

The age of 30s is the most important moment in our life, I guess. -> The most important moment in our life happens in our 30s, I guess.

It is a good to start or to​ decide something new. 

=> Corrected : The sentences are corrected grammatically. 

For me, getting married is one of the biggest affairs, so it should make it on the most important age in our lives. ​

And, it is the same for both genders. ​

(09/28/21)

-비가 오나 눈이 오나 하루도 안 거르던데. : No matter what happens, he(she) keeps it. -> That guy never misses a day, rain or shine.

-괜히 사탕발림하지 마세요. Don't tell me a white lie. -> Don't sugarcoat it.

-전 숨쉴 틈이 없었어요. I had no time to have a break. -> I hardly had time to breathe.

=> Your sentence has a correct grammatical structure, but this has the correct usage/ expression.​