I got there 10 minutes earlier than I said I would.
I arrived there 10 minutes later than the time we had arranged to meet.
1) I got there 10 minutes earlier than I said I would.
「言ってた時間より10分早く着いた。」
「そこに着く」は get there と言えます。
2) I arrived there 10 minutes later than the time we had arranged to meet.
「約束した時間より10分遅れて着いた。」
「着く」は arrive も使えます。
「約束した時間」は the time we had arranged to meet や the time we had promised to meet などと言えます。
ご参考になれば幸いです!