Now I'll turn over a new leaf.

现在我的人生将翻开新的一页。

youdao

We're going to let bygones be bygones, and try and turn over a new leaf.

我们要既往不咎，试着开启新的一页。

youdao

He realized he was in the wrong and promised to turn over a new leaf.

他认识到自己错了，承诺要重新开始。

《柯林斯英汉双解大词典》

But Mr. Barron seems to have turned a new leaf during this congressional campaign.

WSJ: Candidates Skirt a Political Circus

"Indian Banks: Turning Over a New Leaf", by Ananda Bhoumik, Fitch Ratings, November 2005.

ECONOMIST: Sources and acknowledgements

To turn over a new leaf means to flip to a new page.

CNN: In the new year, be a first responder