How to post pictures and redesign my background to something original?

So, yes I tried following the directions of how to d/l the software to post pictures. I did everything correctly but I still can't figure out how to access the software to post them. Frankly I probably didn't even need the software and have now cluttered my dad's comp even more. Also I want to redesign the background on here, can anyone help me? I feel so computer illiterate! I want to be able to do this but can't for lack of knowledge or ability....but I am open and willing to learn! Pleas help me!
PS If you are someone who happens to read my blog but don't really know me feel free to post at any time. Oh man I feel really odd saying that cuz probably no one really looks on here other than, Ron, Esther, Mike, Johanna and sometimes Tiana. Not that they aren't important cuz they are very important, can someone give me a shovel to dig this hole even deeper.....