Before you even think of getting your own webshop, make sure to acquaint yourself with the laws that govern online retailing. Also, make sure to study the market concerning your product segment thoroughly. Not every product is always in demand, and the popular market segments may already be occupied by other webshops in your region. 

When you have completed this research phase and start the development of your website, there are a few important things to keep in mind. First, for some products you need a certificate to be allowed to sell them, so in that case you have to make sure that you get this before you make your first sale. Then, these days it's a must to offer various payment methods and it is very important to have a structured delivery system for your products. Luckily, most delivery and payment platforms consist of API's these days, which can be implemented quite easily. Finally, never forget to ask for a warranty service from your suppliers before you start making your first sales.