Hi and welcome to the forums.
Regarding the differing IP addresses you’re seeing; the 174 address is the one assigned to your connection by your ISP and the 192 address is the one assigned to your computer.
My guess is that you have a router (or modem/router) that your PC connects to. Correct?
You can think of your router as having two network interfaces, one outward facing towards the internet (or more correctly towards your ISP) and the other inwards facing towards your LAN. When your router connects to your ISP, your ISP assigns the internet facing network adpator the 174 address. When your PC connects to the router, it is actually connecting to the inward facing network adaptor in the router.
If you have a look at the adminstration console of your router, you should be able to find a setting for what IP address range you want the router to use for the internal LAN - this is where the 192.168 numbers come from.
It is safe to publish the 192.168 numbers online, as the 192.168.X.X address range is what is known as a private address range (as are 172.16.X.X and 10.X.X.X). Private address ranges are known as non-routable and cannot be used to send data across the internet.
Q. If they can’t be used to send data across the internet, how come I can surf and send emails?
A. Remember when I said your router has two network interfaces? When you attempt to use an internet resource (browse, email, etc.), your PC (I’m assuming 192.169.0.31) is actually sending your request to the inward facing IP address of your router (probably 192.168.0.1). The router records what internal IP address sent the request and the router then passes your request to the outward facing network interface (the 174.X.X.X one) in the router which then forwards on to your ISP and then on to the internet. As a result, your request arrives at its destination with the 174.X.X.X address, not your 192.168.0.31 one.
When the outward facing interface receives a response, it passes the response to the inwards facing network interface which then looks up which internal (192.168.0.X) address originally sent the request. It readdresses the response and then forwards it back to your internal IP address.
This is how your internal, private, non-routable IP address is able to request and receive data from the internet. Your internal IP address never gets to the internet - your router is acting sort of like a broker for your request.
Regarding the 192.169.0.31/24 - the “/24” is what is called a netmask and is used to signify a logically visible subnetwork. For an more complete explanation, have a look at Subnetwork - Wikipedia. It’s a good article, but can be a bit heavy reading. It is worth perservering with though, particularly as you will come across this in your studies.
Hope this helps,
Ewen 