GST

For any online business, a GST number is mandatory regardless of your turnover. If you have a GST number, then you can easily trade across states, enhance business credibility and compliance, and claim input tax credit on purchases.

You only need to register for GST if you are earning more than 20 lakh rupees. Since you are making less money than 20 lakhs, you do not need to register for GST.

For your online store, even if your revenue is minimal, you may need to register for GST in India. If your annual turnover is below Rs. 20 lakh (In some states its Rs. 10 lakh ), you are not required to register for GST.
But as you mention, you are involved in both interstate and foreign transactions, you need to register for GST no matter how much business you do.
With your expected minimal revenue, registering as an individual (sole proprietor) with a GST number is advisable for simplicity and compliance with e-commerce requirements.
It’s advisable to consult a GST specialist who can provide personalized guidance based on your specific situation.