HELP! Need help setting up network router

Hello, I have a Linksys wrt1900acV1 and I am wanting to use it as a “wireless switch” to hook Ethernet devices without having to run a large cable through out the house. I am try to hook up to the 5ghz band for best speeds possible. My other router is a Netgear XR -500 on stock DumaOS software. I had it working once but quickly saw that my SSID was open(dangerous) and tried logging back into the router but I couldn’t find the IP so I reset it back to default and I’m stumped once again! I should also note I am a beginner using OpenWRT/LEDE(whatever one it truly is) software!

Are you running multiple VLANs? (If you just got a puzzled look on your face, the answer is most likely "no", unless you have a "guest network")

If no VLANs that you need to trunk to the second router, "WDS" is probably the easiest way to configure this, if the DumaOS supports it. is one tutorial on how to accomplish the task. may provide some help as well.

I’d suggest you start with the Quick Start Guide. Then, if you get stumped, ask specific questions about configuration options.

Thank you I will try it out. I will come back in a day or two with an update

I guess I got it working, however it acts flunky with the Xbox but works fine with ps4 and computer. I just have to manually put up address for each device but for the most part it works.
(BTW the documentation you guys provided was somewhat unhelpful I just ended up figuring it out on my own, but nevertheless thank you for the help!)