In brief:
Don't worry so much about domains for now, you'll just get confused, accept that they are a named boundary for someone's administrative control (private individuals can have their own domain, ISP's have domains, google have many domains).
Networks are a collection of connected devices able to talk to each other.
In long:
LAN (Local Area Network): You have a computer, it is connected to a device in your local network which acts like a kind of comms hub, all the devices in your local network are probably connected to it & therefore each other.
Internet & WAN (Wide Area Network): Networks that span a geographically wide area are called WANs, don't worry so much about this for now I raised it just to get you thinking about local-vs-remote & hubs+spokes, just know that the internet is a very, very large network of all devices that are capable of reaching & talking to each other using the various protocols and media in use therein. Your LAN has a connection to an outside network which we all know as the Internet. Local devices can reach the Internet through your Default Gateway.
Default Gateway: called such because it is the 'gate' that leads to 'other', non-local places, things beyond your local network, and default because there could be more than one so you need a default in case of any doubt. If something cannot be found locally or is known to be located in another network, well, guess which route we'll be taking? That's right, and yes, that's why routers are called such, anyways...
At this point I recommend you grab a nice big pad & start drawing a diagram, hub & spoke style, where your PC is a node connected by a spoke to your gateway device (the box supplied by your ISP) which itself is in turn connected to another hub (something in your ISP it talks to/thru). To flesh it out with details press the "Windows logo" + R keys on your keyboard to open a run dialog, then type cmd
then hit Enter.
Copy and paste this code into the command line window you just opened and hit Enter:
ipconfig /all
This will show you all the IP configuration for your system;
If you are using wired networking, scroll up & look for "Ethernet adapter".
If you are using wireless networking scroll up & look for "Wireless LAN adapter".
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Physical Address: aka MAC Address, hex, unique to that specific network interface, gets assigned an IP address
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DHCP Enabled: autoconfigure networking protocol, is either Yes|No
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IPv4 Address: 4 octets of Internet Protocol v4 networking address for this interface on this PC in the LAN
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Subnet Mask: a topic for later, if at all, probably not, may cause insanity, stick with 255.255.255.0...
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Default Gateway: where your computer looks to reach outside of the LAN, it is the IP address of the device likely provided by your ISP, and would be the one you put into the address bar of your web browser to find it's management pages, if it has any
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DNS Servers: the address(es) of the Domain Name System server(s) being used, DNS is the telephone directory used by and for computers to look up each others names to find the addresses where you can dial them up and go "WazzUuuuuuuuuuuuup!"; when this borks out it is the most common cause of "The internet's broken" complaints, becoz, y'know, fb.com can't be found...
Use this tool to scan the LAN for your devices & gather their details for your diagram: SoftPerfect freeware Network Scanner
All you need to do is give it a start IP and an end IP to scan between, for the IP address you posted earlier it'd be: 192.168.0.1 - 192.168.0.254