Need advice on setting up an online store

Hi, I am planning to set an e-commerce store online, but do not have much details about the nuances of running a digital shop. Does anyone have experience running an E-Commerce store and managing it? How much will it cost to build and run an online store, I am expecting around 50-100 orders per month initially. I tried setting up a catalogue in social media, but I feel like it's not my cup of Tea, so a basic store will do. For now, most of my customers are repeat customers, so I can just do the marketing personally. So for now I don't need much customisations, some inventory and customer management, taking order's and online UPI payment. Any ideas or suggestions are welcome!