"After the lesson, I looked up what I wanted to say."
"I went over what I wanted to tell you after the lesson."
"After the lesson, I looked up what I wanted to say."
"after the lesson" 「レッスンの後に」
"I looked up ~" 「〜を調べてみました」
"what I wanted to say" 「伝えたかった事」
"I went over what I wanted to tell you after the lesson."
"I went over ~" 「〜を勉強した」・「〜を調べた」
"what I wanted to tell you" 「あなたに伝えたかった事」
I looked up what I was trying to say at our last class after our lesson.
I looked into what I wanted to say to you at our last lesson when we finished our class.
この場合、次のような言い方ができます。
ーI looked up what I was trying to say at our last class after our lesson.
「前回のレッスンで言おうとしていたことをレッスンの後に調べてみた」
ーI looked into what I wanted to say to you at our last lesson when we finished our class.
「前回のレッスンで言いたかったことをクラスを終えてから調べてみた」
「調べる」は to look up や to look into などと言えます。
ご参考まで！
オーストラリア 
カナダ 
