There is honestly so much out there that can help you know instead of believe.

Try astral projection. learn how to do it and buy a book on it.

get your friend to hide some numbers in his house on a papper or some object on top of a particular shelf in his home.

when you astral project try to go to that location and find out what the object or numbers are. when you have the number or what you think is there, confirm it with your friend.

compare the results.

repeat and see what happens over and over.

You can go down the whole rabbit hole trying to figure this stuff out...it's really for the dedicated honestly but you can dabble and experience some things for sure.

Astral projection is by far the easiest thing I could think of for a skeptic who wants to know more about the unknown..it's not a easy thing to do, but it's the easiest one out of them all without going to far down the rabbit hole.

To aid in your Astral projection study if you take it up, I'd recommend learning about Meditation and the Chakras. You don't even have to believe, the vibrations during astral projection and experiences you will have first hand if you do this will be enough to knock your socks off if you stay at it long enough :) .

learning about the energy system aka Chakras is a good part in aiding your astral travels or attempt. Meditation as well. This will help your mind and body get in a trance like state faster and more effectively so you can go out of body.

You may also explore your house, and see other people walking around it, see yourself sleeping, visit friends/other places, etc... give it a go, record the results and tell me what you experience if you want, be happy to know how your travels go.