Can I modify the code myself?
Yes, but you must always keep in mind that if you modify the code yourself then you do it at your own risk. You must to know what you are doing, otherwise errors may occur. Make sure that everything works properly. Or ask someone who does this for you.
CSS Customizations:If you want to make changes to the theme through CSS, edit file “stylesheet.css”.
This file is located in:
If you would like to edit a specific section of the site, simply find the appropriate label in the CSS file (use Firefox extension called “Firebug” to do that or “Chrome/Safari inspector“), and then scroll down until you find the appropriate style that needs to be edited. If you do not know how to use “Firebug” or “Chrome/Safari inspector”, you just search on Google or YouTube. I believe that you will find some good tutorials.
Note: Is a good practice to backup your files before making any upgrades or changes.