Newbee Guide to Octo4a?

Brand new to Octoprint. I just installed Octoprint Octo4a on my android Samsung S7 old phone. Two issues: 1) Network questions and 2) How to access and use Octo4a. I have read several writeups on Octo4a and they all assume you already know how to use Octoprint and just say "android works just like Octoprint". But I've never used Octoprint and have no clue how to get access to the phone. I keyed in my local network IP address (192.168.1.X:Y) into my browser and get nothing. I am not a network expert and rusty on the little I know. Is the "Y" part of that address the port forwarding? Is this automatically port forwarding and allowing access from the internet? Security issues? How to secure the access from the internet?
2) Does anyone recommend the best "from scratch" writeup or YT on how to access and use Octo4a effectively? BTW, the phone keeps turning itself off. How do I lock Octo4a to "On"?

What did you already try to solve it?

I've read writeups and watched several YTs and they all assume a level of knowledge that I don't have on Raspberry Pi Octoprint.

I'm not an Octo4a expert but I can answer some of your questions...

The ":Y" is the port number. If omitted from a URL it defaults to 80 for "http://" and 443 for "https://". The ":X" would be the port assigned by the DHCP server (most likely your router) in your network. It could also be assigned manually. Tell us how you determined yours?

"192.168.1.x" is a private IP address and is not accessible from the internet. Given your admitted lack of network expertise, I strongly recommend you not attempt to access OctoPrint from the internet at this time.

The number of Octo4a users in this forum is minimal compared to the number of users in this forum that use a Raspberry Pi and probably much smaller that the number of users who use something else like Windows, or MacOS, or other SBCs.

Hopefully, one of those Octo4a users will respond with an answer to your question. My personal recommendation is to "bite the bullet" and get a Raspberry Pi. You can use https://rpilocator.com/ to find one. An RPi Zero 2W or an RPi 3B+ will be plenty (i.e. you don't need an RPi 5 or even an RPi 4) and can be found relatively cheaply. You will need a proper power supply (and a USB cable with the correct connectors, the Zero 2W especially). Once you have things working, you can 3D print a case!