I cut my boyfriend's hair for the first time. It went well!
I tried cutting my boyfriend's hair for the first time, and it was a success!
ご質問ありがとうございます。
①
"I cut my boyfriend's hair for the first time."=「始めて彼氏の髪を切ったよ。」
"It went well!"=「上手く行った!」
②
"I tried cutting my boyfriend's hair for the first time"=「彼氏の髪を始めて切ることに挑戦したよ」
"and it was a success!"=「そしてそれは成功だったよ!」
ご参考に!