It is empty, because you need to configure it! 1st hAP will be CAP Manager and the other will be just CAP (Access Point assigned to CAP Manager). The advantage is that you manage all your access points (if they are assigned to CAP Manage) from one place! You will see all clients connected in on place. Otherwise, to locate a client connected you have to login to 1st or 1nd MikroTik device.
By default MikroTik assigns IPs starting from the highest number (254, 253, 252, etc.). You can manually assign IP by MAC address in DHCP leases, and then it will assign always the same IP to the specific MAC.