Go Settings -> Design & Style on top menu.
The EASY way for non-experienced users is choosing "2. Template Based" and clicking CLICK HERE TO SELECT THE TEMPLATE FOR YOUR BLOG link. There you can choose one from 60+ ready made templates which will change view of your blog instantly!
If you need to change just font, text size or color or background color: please choose MODIFY YOUR BLOG STYLE (DEFAULT FONT FAMILY, COLOR AND OTHERS) option. Also below this option there is a link to choose a graphic background image for your blog - SET A DIFFERENT BACKGROUND FOR YOUR BLOG.
Advanced Users who can edit HTML code, can modity template directly - choose EDIT DIRECTLY THE HTML CODE OF YOUR BLOG TEMPATE .
If you have more questions - Contact us, we will help.