Learn Web Development
This is the first thing that you need to do. You should be able to make websites and know how the whole process works. For this you will need to learn a number of coding languages that are used and stay up to date with the latest trends and ideas that are being used in the industry. Make a portfolio of websites that you have designed as it will reflect well for you when meet a potential client.
Understand the Needs of the Business
E-commerce websites have their own plans and their own needs. They need to be made in a way that they are friendly to the customers while they provide maximum facilitation to the people running the website. It must be easy to update as new products and price changes are going to be updated on almost a daily basis.
Do a Course
It is even better if you do a course in the field. This will allow you to learn from the experts and have a better understanding. You will learn about tools such as the shopping cart which is probably one of the most important aspects of e-commerce. Make sure that you learn well and understand or practice the skills during the course as well. You can even make practice sites which you can later modify and sell as well.
Start working freelance on small projects. You probably can do well if you make a web store for a local grocery store. They will not be entirely relying on the website as you can correct any bugs and learn the trade while you get paid as well. In smaller sites, it is easier to fix bugs and clients are not as fussy either.