Ok, this was a problem I had 6 months ago, and I decided to drop it, and stop wasting my time with it. I decided to tackle it again, and still no luck, I have spent 4 hours on this, and no luck what so ever, and I am getting really mad, I would use vulgar language, but I will refrain from doing so.

What I am trying to achieve is when I connect my tp link mr3040 to router via ethernet connection on eth0, I want to connect to my 3040 via wifi(wlan0) and browse the internet, and of course I cannot browse the internet, I can ping when I ssh into the router, I first thought it was a firewall issue, but I disabled my firewall, and still had the problem persist.

Here are my dhcp,firewall,network, and wireless files, sorry for the term "cute" in my files, I was being a smart A-- and decided to call it that. Also please tell me what routing/zones I can remove in my firewall, I cluttered too much in there, I believe.

wireless https://pastebin.com/tfB9cWQt
network https://pastebin.com/giVxd3v0
dhcp https://pastebin.com/ZyeaXZHK
firewall https://pastebin.com/cu7FsAzU

If you want only a basic wired to wifi converter, that is called a "dumb AP" and is set up this way:

Start with a default configuration.
In /etc/config/network, change the LAN IP to something that is not the same as your main router, but in the same range.  Remember this setting this is where you will log into the router.
Add option gateway  and option dns to lan, the IP address pointing to the main router.  This lets the AP's CPU access the Internet, for example to set the time of day clock.
In /etc/config/dhcp, put "ignore 1" under LAN and delete the IPv6 modes.  Your clients will receive their DHCP from the main router.
In /etc/config/wireless, create an AP and attach it to the lan network.

You don't have to set up any firewall.  A dumb AP bridges everything through since the Ethernet port and the wifi are in the same network.

Reboot the router and plug the Ethernet cable into your main router instead of the PC.  You should now be able to connect by wifi and have access to the LAN and the Internet.