Portal config on RB750 UP

Hi - I’m new to mikrotik products and am looking for a little guidance on the proper config. Here’s a quick overview of what I want to setup:

  1. Closed network - there’s no outside link to the internet.
  2. 750UP - as DHCP server
  3. AP#1 (Ubnt RocketM as AP) with no security - users can join AP without login to AP.
  4. AP#2 (Ubnt RocketM as AP) with WPA security.
  5. Server w/ fixed IP connected by wi-fi.
  6. Clients connected to AP#1 directed to captive portal - users/client devices are automatically directed to a URL on the network.

Thank you in advance for your time.

Graham