Passover and Succoth have different historical and theological meanings. The former is based on the experience of the Israelites in Egypt and the second is based on the wilderness experience.
From this point alone, we can begin to see the differences. Passover remembers God's deliverance from the Egyptians. From this perspective, the plagues of Egypt are important. However, the last plague is the most important when every firstborn was killed, because of the hardness of Pharoah's heart. The essential point is God's deliverance of Israel and the judgment of the oppressors.
Succoth, otherwise known as the Feast of Tabernacles or the Feast of Ingathering, celebrates the wilderness experience. The fact that the Israelites are bid to live in booth shows that they are in transition. More specifically, this shows that they still on a journey to the Promised Land. The encouragement here is that there is a goal in view and so they must persevere. Knowing there is an end in view is very encouraging.
If you want to make this applicable to teens, then you might want to focus on God's delieverance. You might want to underline how all of us need help and delieverance at times - the meaning of Passover. Faith can help in these situations. When it comes to Succoth, you might want to emphasize the need to presevere during hard times.