Are you having trouble astral projecting? Have you tried any methods so far? If so, what methods?
If you are having trouble, I suggest the "roll out" method. It's a common one and I believe it's the easiest.
You should lay down, making sure the room temperature is stable, not too cold and not too hot, just right.
It's preferred if you draw out a mat and lay on the floor, but you can also lay on the bed. The floor is preferred since the goal is to go into deep state, not to sleep.
Take three deep breaths. Afterwards, focus on your breathing. Breathe however you feel comfortable, but just keep it calm and in the same way.
You should let go of all the stress and relax. From this point on, anything that worries you, anything you think is nothing. It's meaningless. Nothing matters. Just "let go" of each of your body parts. You can either start from your head to your feet or feet to your head, concentrating on each body part and letting it go, as if it's not there any more. You may get an urge to scratch yourself but just try to ignore it. Your body is trying to get you to do something because it's not used to be immobile. Become unaware of everything around you. Don't think about anything. Just focus on the breathing, and you'll eventually be thoughtless. If not, don't worry. Just try to push away all thoughts. And make sure you become so relaxed that you feel like you don't even have a physical body anymore.
After you have relaxed your body and calmed your thoughts, you should feel like you are calm and body less. I don't know how you may feel without moving at all or thinking little to nothing. You're in a rare state where your body seems to be resting but your mind is awake.
This is the tricky part. You have to "roll out". You know you are laying down, your body is immobile, but you must roll out to be free. It may not work the first time, but you should still try. What I do is try spinning around inside my mind till I have enough "astral awareness" to roll out. Try not to think about it, just try doing this part.
If you manage to do this, then you are free. The laws of physics and reality don't apply to you. You could fly just by thinking about it. You may be in your room or you may be somewhere mysterious. And don't worry, you're not dead. You're just in the astral realm. You can go anywhere you wish. You can see the cosmos, visit places, etc. Astral projection is a personal experience so it's different for everyone.
And make sure if you want to go back, you just close your eyes and gently think of yourself shifting back in, as if guided by a stream. If you meant harmful astral entities, you can shield yourself and create astral weapons just by thinking about it.
I hope this helps. If not, I'll search for some good links for some different astral projecting methods to give you. Everyone is successful with different methods.