Network extension help

[newlore]

Hey everyone, I'm in need of some help.

 

I need to increase the network wireless range at a horse stable.  It's not super fast internet, but enough for basic usage there.  At about 10-15 Mb/s

The router on location is a TP-Link AC1900

https://www.amazon.com/TP-Link-AC1900-Smart-Wireless-Router/dp/B00PDLRHFW/ref=sr_1_3?ie=UTF8&qid=1547152487&sr=8-3&keywords=tp+link+router+archer+c9

I just bought a TP-Link AC1200

https://www.amazon.com/TP-Link-Extender-Repeater-Housing-RE305/dp/B01N8ROH7G/ref=sr_1_10?s=electronics&ie=UTF8&qid=1547152886&sr=1-10&keywords=tp+link+ac1200

 

I'm not the greatest setting up extenders, but I was kinda hoping... is there a way to have the WiFi hand-off the connection between the two devices?  If someone is farther away from the router and is closer to the extender, there is no connection interruption when moving closer to the router.  Hopefully this makes sense.

The router is on one side of the stable, and I want to set up this extender on the other side where people mostly sit around.  I know I can run an Ethernet cable from the router to the extender, I plan on doing this actually.

 

Please help!

 

Thank you LTT Community!