at the first time是在第一次时
I was terribly nervous at my first time.我第一次时好紧张
for the first time第一次
I did this for first time.我第一次做这个
at the first time是在第一次时
I was terribly nervous at my first time.我第一次时好紧张
for the first time第一次
I did this for first time.我第一次做这个