Likely got this part: but there are
two password for the Wi-Fi – one for the 5Ghz and 60Ghz. So need to change both. But other than that should be good to go.
Also they use "auto" frequency for 5Ghz by default. Default config creates an active-backup bond, with 60G and 5Ghz interface in it. But even if 5Ghz is backup, it's possible you might want to select a channel if there is a lot of interference in your area. Interfere at 5Ghz is slightly less of a concern here since distance cannot exceed the 60G range, but something to consider. There is a scan button that might help pick one, but no SpecA.
We are experienced network / virt engineers but RouterOS is totally new to us.
You'll do fine. RouterOS it's more of an erector set of the various protocols/interface/etc. & all devices have same software features. e.g. If you wanted turn the Cube60ACs into a pair of VRRP-enabled routers running OSPF for a LAN, they'd work (but limited in capacity) and config be same as on a bigger router. Not saying to do that but that's how RouterOS works.
One thing Mikrotik-specific to note is the winbox app allows Layer2 access to routers via MAC address. That can be helpful to get into these Cube when bridging since the default IP are likely in a different subnet.