Its an amazing experience! As mentioned by some of the other users it can take months/years to master, however you should be able to experience the first effects within your first few attempts.
There are several phases in astral projection, once you experience the first few phases (sleep paralysis, dizzyness, chakra activity, etc) you will never look back.
This experience will verify the truth and will give you the confidence to progress to the next phases of astral projection.
You don’t need to pay anyone money to experience it, there is enough free information on the internet about it. You can also download some programs that emit binaural beats through your headphones. These frequencies generated will induce alpha brainwaves (the state in which your mind is awake and your body is asleep) – Ideal for astral projection.
I have tried the brainwave generator program a couple of times, this is definitely a shortcut method (as opposed to lengthy meditations). Usually within the first 10-15 minutes you will experience some results. This may only include paralysis, increased chakra activity (ie, tingly body or racing heart), however several attempts will yield results and will lead you to your first conscious OOBE.
Do not be dis-heartened by those who don’t believe. They are young souls, who are not ready to take on such information. These non-believers are the same types who refused to admit the world was round just because they couldnt ‘see’ gravity.
It is not their fault that they don’t believe, they simply are not ready.
P.S to answer your question about other people seeing you…
Sometimes when out of body, you will see other entities. Some will see you, some wont.
Some will be people, some wont.
Some of the people you see could be others that are having an oobe or they could be real people.
This depends on which dimension/realm you have projected into.
If you are in the physical dimension you may see real people.
If you are in the astral projection it is possible you will see spirits/astral bodies.
It is very rare that you will be able to project into the physical dimension (and stay there for very long). Physical dimension is the world we live in today.
The astral dimension/plane is a copy of the world we live in however things, objects can slighlty differ. These 2 planes can often be confused for each other, but you will see this for yourself if you decide to continue your journey.
I hope you have found this info useful, let me know how you go.