If you make a good case for yourself and submit a solid application, you never know, so don't underestimate yourself!

万一你很好地展现了自己，提交了一个可靠的申请呢？你永远不会知道结果如何，所以不要低估自己！

The biggest piece of advice I would say is don't underestimate yourself.

我想说的最大的建议是不要低估自己。

The most important thing that I've learned is this: Never underestimate yourself.

我学到的最重要的事情是：永远不要低估自己。