What are the BEST FREE marketing tools and strategies to execute ?

[Sindy]

I'm currently in the process of launching my online store. But as a sole entrepreneur there's only so much I can handle. What should be my focus point towards driving targeted traffic and creating a large support group( followers, likes, etc) ?
I currently using Instagram, Tumblr, Facebook, and Craigslist. I'm currently looking to expand into youtube videos and creating a wordpress blog.

Can anyone provide any insight into Effective Marketing for Free. Any Tools, Sites,and etc ?

Thanks, Your information and expertise would be of great value.
Yes, I have been having a Google analytical account which tracks everything for me. But how can i generate more targeted leads without paying for advertisement ?