The second is singing, which can't be practiced overnight, but it is also effective to sharpen your gun when you get cold feet. Singing requires the strength of Tian Chan, that is, singing with your stomach, breathing with your stomach and singing in bed can all be exercised. There is also intonation, so you can only listen more and practice more. If your voice is not high enough, you can use falsetto in the high-pitched part, but pay attention to the conversion between true and false sounds so that the conversion between them is not so stiff. If you really can't sing, you can consider several voices in the venue.
If you want to win the prize, I suggest you find a professional teacher!