Flipping business: What do I need to report?

Over the past few months I’ve been buying selling and collecting discontinued items such as Oyo minifigures. I’ve been buying 2 purposes; flipping majority, and collecting some. I’ve done my business across a few platforms, ranging from Reddit, Facebook, eBay, and Mercari. I haven’t made enough on Mercari yet to file a W2. But I’ve made well over a grand in profit doing business through chats and PayPal. I’m trying to figure out what do I need to report and what not to. Im new to this flipping business and want to have 0 issues with the irs! 🙂