What does success mean to you? This is a broad question to an already broad question :-)
Try to identify what interests you about e-commerce and aspects of e-commerce that Analytics can help improve? So many aspects are involved in making a sale online such as recommendations, product placements, advertisements, marketplace dynamics, A/B testing, customer support, merchandise returns, reviews, etc.
Start with identifying what is happening in the broad category of e-commerce.
Look at startups in this field that are building solutions for e-business. Research VC firms investing in this general area and then look at what their portfolio companies are doing.
Go to their websites, check out the career sections, find any roles that look interesting, and read what those roles involve?
Read white papers about E-commerce analytics (e.g., https://www.conversific.com/blog/ecommerce-analytics/).
Learn about the work being done in using Computer Vision in Fashion. What is Instagram doing in the areas of e-commerce? What is social selling?
There is a lot happening in this field and you can start to read and learn more about topics that are not specifically related to Analytics. But once you gain awareness in the general area of e-commerce, you will also start seeing more and more opportunities to apply Analytics in e-commerce.
Best of Luck.
The discussion shared above was part of many Q&A sessions Harsh Singhal conducted with Data teams at various companies and colleges.