> Use c7000 as AP [...]
That should be possible.
> [...] connected to my cn1000 cable modem
Why? That would appear to be approximately pointless.
> What settings would I have to change so I can use the c7000 as ap and it
> should handle DHCP as it looks like the cm1000 does not support this.
A CMxxxx is a modem, not a router, so it will not serve as a DHCP
server.
A Cxxxx is a modem+router, but it has no Ethernet WAN/Internet port,
so it can't be used as a router with a CMxxxx modem.
If a Cxxxx is configured as a wireless access point, then that
configuration would disable its DHCP server.
You appear to want to use your C7000 as a router with an Ethernet
WAN/Internet port. It doesn't have one, so you can't do that. Although
configuring the C7000 as a WAP may be possible, if you do that, then it
still won't be a router.
Possibly interesting, but only if you get a router:
https://community.netgear.com/t5/x/x/m-p/1463500
That's written for a Netgear C6300-as-WAP, but the steps are about the
same for any other router (any make/model) which lacks a one-step WAP
option.
But you apparently want a router, not a WAP.
