I think you can find them just about anywhere (if you're talking about the codes to make your page all bling bling sparkly and all that) and just copy the code and paste it into the general info of your page parameters and it should work. Though I may be wrong, I'm FAR from being the resident computer genius. :)
Css codes can be found in the NING directory. If you go to the main NING page and type...lets just say pagan CSS themes, there will be a bunch of preset pages to choose from. after copying the code , come back here(to your edit my page) and go to the advanced option(tab). paste, save and done. its pretty easy. If you just copy that whole code you don't have to do any other codes unless you do want to add some random/sparkly pics then you just copy and paste those anywhere in your "about me" type sections
oh and PS just so you know it took me FOREVER to figure out there were preset pages and I spent HOURS on my first page editing all the little details lol. Don't feel bad. There is a group on this site with preset codes too, I used one but then the host exceeded their bandwidth on photobucket and it messed up my page...so I don't recommend that one until she fixes or upgrades her photobucket profile.