Could yoga help me for better sleep?

Definitely. It should help but for sure it will not hurt to do for many other good health reasons.
Yoga breathing. There are different styles of yoga. Some of them are quite stimulating to the nervous system and others are more restorative. Look for a yin yoga class and also those that include breathing exercises called pranayama. You will learn strategies to recognize when you are "wired" and start to use them to get yourself calm. Good restorative sleep is the reward.