Technical Difficulties

I have decided that blogging is not easy for everyone. I don't know how to change my settings so that the past few posts are visible. The old font color was set to white on a black background and now I have a white background...(yes, I can figure out how to change the background but not the font) which is causing me to have an aneurysm just trying to figure it out! I know how to change the color of the font while I'm in the composing stage...but what about previous posts? Also, my picture once fit the space at the top and now it appears to be too small and off to the left......HELP!!!! I'm so confused!