Now that you're thoroughly confused, let me try to confuse you a little more.
First of all, goodguy is correct, the D3300 is a better camera. Or maybe I should say it's the camera with more potential. The ability to change lenses or add on flashes means you can adapt the camera to a myriad of situations, and being able to shoot in low light is a huge advantage. So let me explain why I suggested the RX-100 for your situation.
1. Wifi: Sony cameras can sync to your phone and immediately transfer the photos you just took. This means you can take a picture and two minutes later upload to Instagram, without needing cables or a computer. Now, for many pros, this is a non-issue, because they shoot in Raw and edit every single shot with Lightroom or Photoshop, so they have to transfer to a computer. But if the only editing you intend to do is Instagram filters, having to go to a computer will be a huge hassle.
2. Size. The RX-100 is significantly smaller. I was amazed the first time I saw it that they could pack so much into such a tiny package. It can easily fit into a coat pocket, and probably even most men's jeans. The D3300 would need its own camera bag.
3. Lens. There is only one lens on the RX-100, but it is a very good lens, much better than the kit lens that comes with the D3300. It can open up to 1.8, which helps with low light and bokeh. Now, if you purchase a better lens for the D3300, that advantage goes out the window. But if you don't intend to upgrade the lens on the D3300, then the RX-100 would be better.
Now, if you want something that's sort of halfway between the two, you might want to look at the Sony a6000. It has the ability to sync to your phone wirelessly, is slightly smaller than the D3300, but has the same size sensor. In fact, Sony makes Nikon sensors. The a6000 can change lenses (although you have Sony's smaller lens selection to choose from.) I believe in-depth testing shows the D3300 as having a slight edge in low light, but I don't think it's even a third of a stop whereas they will both beat the RX-100 by a ton.
If you have a camera store nearby, it's always best to go in and take a look. These cameras are so popular that even my local Best Buy carries some version of each of them.
Here's a link comparing RX-100 to D3300:
Nikon D3300 vs Sony RX100 IV
Compare the Nikon D3300 vs the Sony Cyber-shot DSC-RX100 IV
And here's a link comparing similarly priced interchangeable lens cameras:
2015 Roundup: Interchangeable Lens Cameras $500-800