If I were you, I would prefer buying a macbook, a smart watch and a gopro camera because that's all what I need currently. So shopping online should be based on your needs.
I think that nowadays you can buy almost everything online, gadgets too. I have recently bought an Apple watch online for a very cheap price, I have found a site where you have to open mystery boxes online, and I tried and won the watches! I think I have the luck on my side. Good luck to you too! :)
You can buy all sorts of cool gadgets online. In fact, almost any gadget that you can find in a store, you can also find online. Some of the coolest gadgets right now are gadgets that are smart, or use bluetooth. One of my personal favorites is a wireless bluetooth speaker that will connect to any device that is bluetooth enabled.
So most people can play music on a speaker using their phone. You can also find home assistants like Amazon Echo or Google Home.