If you are just starting out and know next to nothing, my advice is to visit the Zazzle forum and find your way around the Zazzle site. Look at what the successful designers are doing as far as setting up a store. There is a lot to learn. It's best to know what you are doing before you jump in and begin. Good designs that fit correctly on products is only half of it. Titles, descriptions, tags, and promoting go along with that.
Finding my way around Zazzle is easy for me now. Even with their continuous changes, I'm able to keep up because I've been doing it regularly since 2007. I don't get crazy designing on every one of the products they now offer. I stick with what brings sales for me.
Every day I get out of bed, make coffee and sit down at my desk and begin work. I love the fact that I can earn a living from my home. It's so great that I don't have to set my alarm and get out the door and go to a regular job! I did that for a long time. I am doing work that is interesting and rewarding because I get to be creative every day.
Parts of my work-at-home lifestyle I like better than others. I can get very distracted making new products using a new design I have created. And I never know (usually for months) if that design will be something customers want.
Along with the designing part, I also "pin" products to my Pinterest boards, Tweet about them, add them to my FaceBook store page, and write a blog post on my website. It all has to work together so that my new design get out there for potential buyers to find.
By the way, don't count on Zazzle to promote you. If you keep searching the Zazzle front page hoping to see your product there, don't be disappointed if it never happens. I am a Platinum ProSeller and have access to the Elite forum, and truthfully none of that has given me any advantages that I am aware of. My sales come from my efforts, and from affiliates who choose to promote my items. (Thank you to any and all affiliates who do!)
In my opinion, it has become much more difficult to earn a living through Zazzle. They now have lots of big brand names competing with the independent designers. And there are many, many more people trying to sell on the site, and some are professionals with a lot more knowledge and design education than I have. In fact, the Internet overall has more people selling things. You must be unique to stand out, and have lots of patience and determination.
My income went way up over the years, and then it came back down. Nothing is guaranteed when you do this type of work, and that is the hard part. Zazzle can spring changes on us that affect our income, and we can't do anything but learn to deal with it.