As stated above, HDMI does not support multiple displays out of a single port; that's only available with DisplayPort. You CAN use the USB-based adapters, but be aware that they are NOT quite the same thing. They use what's called a DisplayLink chip that basically uses your CPU and GPU to compress image data for transmission over USB, which is then decompressed by the adapter and sent to the display. This has a few ramifications. First, the display will sometimes feel sluggish and/or reveal compression artifacts when large portions of the display area are changing at the same time, even when you have USB 3.0 and a fast CPU and GPU. This isn't an issue if you'll be using this display for Web browsing, email, etc, but gaming or full-screen video would not be advisable. And second, battery life will drain noticeably more quickly due to increased CPU and GPU activity.
Note also that this does NOT apply to USB Type-C adapters, since Type-C connectors actually have a real DisplayPort output wired to them, so THOSE adapters would be absolutely equivalent to connecting to a DisplayPort output. But it looks like your model does not have a Type-C connector.
Helpful video to add -