Although it was my first time, I was able to prune the trees in my garden from copying how others did it, and it actually turned out pretty well!
ご質問ありがとうございます。
"Although it was my first time,"＝「私にとっては初めてだったけど、」
"I was able to prune the trees in my garden"＝「庭の木を剪定することができました」
"from copying how others did it,"＝「他の人達のやり方を真似して」
"and it actually turned out pretty well!"＝「そして実はかなり上手くできました！」
ご参考までに。
I learned by watching others do it, but it turned out pretty well.
この場合、次のような言い方ができますよ。
ーI learned by watching others do it, but it turned out pretty well.
「見よう見まねでやったら、結構上手くできた」
to learn by watching others do で「見よう見まねでやる」と表現できます。
ご参考まで！
アメリカ合衆国 
カナダ 
