Changing the Basic Layout -- New Painting

Today I changed the template that holds the format of my blog. I did not like the other one very well, but today I found many more to choose from.
Every once in a while I am going to try to do something different in this blog. Today I tried to understand how to change the template. The main problem I am having is how to get back into the draft and edit it...... I am not tech-ie enough.

I painted this little painting yesterday and today and I wanted to see how it looks when it is on a monitor. Paintings can look different on a computer screen than they do in life. The weak places often show up. I can see that the roofs are too white and so the center, where the point of interest should be, is lacking. .... Now just how to fix it??