MacBook Air 2015 was the current product through June 2017, when the MacBook Air 2017 was introduced.
Which seemingly means you either purchased this MacBook Air prior to the June product announcement, or you were provided with new-old-stock by the vendor. (We're other users like you, and have no insight into the timing and the purchase details.)
USB-A ports don't offer video connections, absent third-party software.
On the 2015 model, you'd need to use a Thunderbolt video adapter.
Apple sells several Belkin mini DisplayPort to HDMI adapters which should work here.
MacBook Air (13-inch, Early 2015) - Technical Specifications
MacBook Air (11-inch, Early 2015) - Technical Specifications
Both models have a Thunderbolt port. The tech specs include a list of adapter options for the Thunderbolt port, as well. If there's interest in showing HDCP-protected digital media content (movies, etc), HDMI or mDP are going to be the preferred connections.