SEO for ECommerce

Hey freelancers! I've just launched a new eCommerce business, and am looking to increase my organic traffic... Was wondering what exactly this entails (content, backlinking, etc.) in order to see significant changes over time. Could you please give a breakdown of the budget, with an estimated cost of your services, as well as other costs (e.g. software) that might improve results? If you could send over any other information related to a quote that would be greatly appreciated. Looking forward to speaking with you!