Question for WAN/LAN Experts

Ok so I don't understand this at all bc I suck at networking stuff.

192.168.1.1 is my default gateway

192.168.1.105 is my LAN ip

82.221.20.235 is my WAN ip (not really)

When I run nmap scans against these 3 ips, here are my results:

82.221.20.235:

22/tcp open ssh OpenSSH 7.6p1 Debian 2 (protocol 2.0)

23/tcp open telnet BusyBox telnetd

80/tcp open http Asus RT-N56U WAP http config

443/tcp open ssl/http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)

Device type: general purpose

Running: Linux 3.X|4.X

192.168.1.1 Default gateway

21/tcp open ftp vsftpd 2.0.8 or later

22/tcp open ssh Dropbear sshd 2015.71 (protocol 2.0)

23/tcp open telnet BusyBox telnetd

53/tcp open domain dnsmasq 2.75

80/tcp open http Asus RT-N56U WAP http config

192.168.1.105: LAN (ifconfig)

22/tcp open ssh OpenSSH 7.6p1 Debian 2 (protocol 2.0)

70/tcp open http pygopherd web-gopher gateway

Device type: general purpose

Running: Linux 3.X|4.X

Port 22: LAN and WAN both running OpenSSH but default gateway is running Dropbear?

Port 23: WAN and gateway running BusyBox but not LAN--port closed?

Port 80: WAN and gateway match 'Asus RT-N56U http config' but not LAN--port closed?

Port 21: open on gateway but not LAN or WAN?

Port 70: LAN running pygopherd, ports closed on WAN and gateway?

*Port 443 Only open on WAN, running Microsoft HTTPAPI but my computer is Linux. It was Windows at one time before I uninstalled it to install kali.

Also....ok so I have a default gateway ip and a LAN ip. So when I port forward using my router's settings, which am I setting? The default gateway or LAN ip address? So confusing

If anyone could help me understand what the hell is going on I'd appreciate it. I don't get it at all. Also I thought my LAN ip was communicating to the outside using my WAN so what the heck is the default gateway about? The services running on my router? Thanks.