what's in the other end of the wan port ethernet cable ?
My modem. It's on and functioning.. the eth1 port has my pc hooked up to it..
Very frustrating.
if your modem bridged, or is it providing more than one IP ?
the modem's LAN subnet isn't by any chance 192.168.1 ?
My Wan line is the com port. Followed by eth0-eth1-eth2-eth3. As of now com is connected to modem but essentially dead
Eth0 is connected to the pc and I had eth1 connected to my WaP but with no internet there's no point.
192.168.1.1 is what I typicly use and it's how I am in the ui of opnwrt.. I know this is so.thi g super simple I am missing
com is a serial port, you hooked it up to an ethernet port ? 
you're not answering the questions.
So yes subnet would be 192.168.1.xyz
if modem's LAN subnet is 192.168.1, you can't have the N5105 use the same for it's LAN, they have to differ.
My apologies it's 3am here I am not I. My best state of mind.. lol tired makes for stupidity
Ok. I usually enter I to my modem via 192.168.0 1 mybad I misread
Changed openwrt to 192.168.9.xxx and it didn't do anything.. still no outside connections just the pc
again, what does the com port have to do with thernet ?
Previously via opnsense I was using the com port to connect to my modem. Then my 4 eth ports I used for my Lan connections.. mainly being xbox pc and WaP
So com port was essentially my Wan. And all local traffic went to my eth 0-3 ports so com was net to home eth was home to devices.
com port is wan port ?
what kind of modem are we talking about here ?
It's a arris docsys 3.1
seems your com port isn't the same as mine, and the "com port" on the N5105 probably isn't the kind you think it is.
post a link to the device you bought.
N5105 Soft Router Fanless Mini PC 4x Intel i226 i225 2.5G LAN HD DP pfSense Firewall Appliance ESXI AES-NI
On a new install try eth1 for wan and eth0 for the lan
You can change the setup once you can access the luci webUI or with ssh