Im so glad to see you are learning about meditation!
One thing I have been told by experts is its important to ground yourself before you go really deep within.
By this I mean, when you first close your eyes and breath deeply imagine your are connected to the earth and her life force you are a part of the
earth, so focus on being grounded to this planet for the fist few mins. This will ensure you wont let negative energy into your body while your mind
is off somewhere else. Also meditating out side is the best, if its nice out where you live that is.
Good luck! and remember don't be afraid, there is nothing to fear, it's just you out there.