I have a Sagaretia Chinese Bird Plum Bonsai tree. I keep it in my bedroom window, but because the sun only hits my window directly in the afternoon, could that effect the growth and health of my bonsai. Or would i have to move it from one side of the house to the other?

I just started to become interested in Feng Shui. I plan to get a book about this subject because I know very little. I thought I heard that if you put your bed parallel to the bedroom window that all of your positive energy will go out the window while you sleep? Is this true? I’ve had my bed like this for years and my life has sucked. Also, I have a couch that somebody gave me. I also read that you shouldn’t take furniture from anyone because of all their negativity could be brought into your home. Is it okay to accept secondhand if you really need something?
I live in an apartment building. The layout of the bedroom is pretty cookie cutter and standard. There is just a parking lot outside the window. I am in a bottom floor/basement apt.