Have you ever felt anything like this when trying to sleep (most likely as a kid)?Absolutely wild!?

There are several possible answers here. You could have been dreaming because your subconscious was thinking about it. Next, you shouldn't astral project without some sort of protection. Before you start staring at that white dot, imagine a beam of light coming from the sky through your head and spreading all throughout your body down to the bottom of your feet. Imagine it surrounds you like a bubble. If you ever decide to travel outside your room, try to focus on keeping a cord with your body, like an umbilical cord. The vibrations are normal. When I was younger I use to think it was my bed shaking. Be very careful though ... the older you get and more "daring" to go different places also gets more dangerous. You are not the only one in that realm. Staying in your home for now is a good way to practice. Tell someone in your family to put something (like a flower or a gl or any object) somewhere for you to see, but not tell you where or what it is. Then when you're astral projecting ask your higher self to show you where the object is that the person put out for you. Then if you go in your house to something, check the next day if that was the object.