Gstin

Hi Team I am an individual looking to start a business of buying and selling online and may look to spin of a offline retail store in a year if it is profitable. At the starting point unsure if it is wise to start as a individual or as a registered firm, the reason being I work alone and do not foresee hiring employees or partners at least in the next 2 years. At the same time, I do want to limit my liabilities. I admit I do not know about GSTIN which I understand is mandatory and need your help in understanding a few details: 1. What happens if I do not charge any GST? I still think it is not fair. The buyers & sellers already pay taxes. With almost 50% going into taxes, what is the point of getting into a business? 2. I would still need to register and get a GSTIN. Is it possible as a individual seller or does it have to be a firm? 3. What is the procedure of getting a GSTIN ? Does it need to be renewed every year or is this a 1 time affair? Please advise as appropriate Warm regards