This is the basic's here
Amazon (FBA) + Instagram + YouTube + Facebook + Twitter + Any social media
Make "Videos" of you or someone using your products. - Upload them videos on YouTube
Grow/Buy Instagram accounts or rent someones Bio to market your E-commerce Site
Signup for amazon FBA and get your products on Amazon with that nice "Shipped by Amazon/Prime". (That will look nice!)
Stock up your Amazon store with products. Have your site pointing people to Amazon if they have prime (Free shipping for them & amazon is loved)
Link your Youtube & Instagram + all social medias on your site to give authority to your site.
Share your videos from youtube on all your social medias!
Basic's are now covered.. I really hope the best for you with your online ventures. It's not easy or hard, but everything is possible & please do test out paid ads when you have the chance
Free Bonus Tip: Find relevant niche pages that are popular (Influencer pages on Youtube or Facebook or wherever) And now you will run a giveaway on their page. Contact the page owner and talk about your giveaway of whatever product that's from you site and be sure that product will be pretty cool and make the people who want to join the contest to share/like/signup on your site. This is the killer know how to get sales. People wants freebies & you have a fresh brand new store so the giveaways will spark interest and get you spread out.