I need an access point that is connected to the main LAN ( WAN IP address is part of LAN IP range ), but only accesses the internet from the main gateway, and blocks all access to the IP addresses on the main LAN. Can a MikroTik access point accomplish this? More than one SSID would be a plus. And dual bands would be nice, but only 2.4 needed.
You could configure AP’s firewall so that it blocks any connectivity from wireless clients except connections towards internet.
The above assumes that AP will not be simple AP (transparent), but will rather create its own subnet (with its own NAT etc.).
The above is true for any Mikrotik device. All of them allow multiple SSIDs (each can be own subnet). If device has dual-band radios, then those can be configured completely independently from each other.