You can sell your electronics online via social media or on your own website.
If you have your own website, you as the seller are responsible for everything yourself. You are fully in charge of organising storage, how payments work, shipping, customer service and how buyers find your listing. Not forgetting maintenance, availability and regular marketing for your listing pages.
It could be easier with an existing website like Amazon
, where you will find numerous options that can help you with your business.