need help with ecommerce site

Hi, I have a website that I need help being worked on, it will be an online grocery store for hawaii. I am using website tonight as my hosting because I am a newb. I have my website already all planned out except I have a couple troubles: I need help with making a user database for my site so people can login, I need help on a shopping cart to my site so my users can buy products Here is the thing, I don't have much money at the moment. But I know my business will do good, This is basically what I will live for, my dream. I will not be able to pay up front when the website is done, We can make a contract or an agreement that I can give you a certain percentage or money for so and so months. I am willing to pay over $1k in total if you just trust in my idea. I know my site will work, i am just technically skilled to do it all.