I have just started an internet store and have zero advertising money. Does anyone have ideas on free advertising to attract buyers to my store?

Create Banner ads to post on other websites that will allow you to promote your site there as well as getting their link on your site with use of their own banner ad as well…great way of networking and yes you could both make monies off of clicks to each other's site. You could network yourself and others through a creative "favorite links page" where you'll be able to display other sites' ads on your site. That's what I'm doing! Takes time…but after your first year, you'll be glad you did this…it helps…you'll need to do some researching on your own to figure out how to make monies using other websites links on your site…depends on the market.