Hello @Steve91,

For your questions, there are two options as reference.
1. For long-distance communication, we will recommend you to set a point-to-point connection.
Which means you will need two of CPEs plus one AP or wireless router and a clear line of sight.

The connection should be like Router----AP CPE)))(((Client CPE----Another AP.

One CPE should connect to the router in the main house to extend wireless signal to the other building, while the other CPE should be installed in the other building to receive the signal from the 1st CPE.
As the 2nd CPE will work under client mode which means to transfer wireless signal to wired signal, so it will not broadcast wireless signal.
If you need wireless signal in the other building, you need to connect another AP or wireless router after the 2nd CPE to broadcast Wi-Fi.

Here is the link you can check the products.

For more details about this application, you can refer to the link.

We have some articles and instructions that might be helpful:
Long-distance wireless connection concerns when using outdoor access point
How can I set up the AP + Client topology successfully

2. If you also want an outdoor Wi-Fi between two buildings, you may also consider using 2 EAP225-Outdoors to build the mesh network and no need the CPE.
And you need use an Ethernet cable to connect EAP to your main router's LAN port inside the house and the distance far from each other need be less than 60m.

As you will also want WiFi in another building, we recommend using two EAPs and above to ensure performance.
 

Because this EAP supports mesh feature, to establish the mesh network, you will need to connect one EAP to the router/switch via Ethernet cable, and the other EAPs will be able to wirelessly connect to each other.
With the mesh network, you just need to power on the other EAPs, and they will not need to connect to the router/switch via Ethernet cable.

Please note that:
1) You will need to configure the Mesh network on the controller. So please download a software controller or purchase a hardware controller like OC200.

2) Normally, it is suggested for you to run the controller all the time. You can check more detailed information about mesh network in the link.
Here is a guide to set up mesh network.