For the DC, you need to install 8 gauge automotive multi strand wire.
20 Amp fuses at the
battery on the DC portion, you are protecting the wire size.
Circuit breakers for AC power. AC wiring needs 12 gauge and multi strand also.
Lots of zip ties to keep the wire held in place.
DC (-) ground to the DC post on the Battery.
DC (+) positive to the DC (+) post on the battery.
AC Ground to the AC Ground on the external Power plug.
AC neutral to the AC neutral on the external power plug.
AC power to the AC power (Black) on the external power plug.