1 - I get that light is flashed in binary to code chips but how does it actually fookin work ? What is the machine emmiting [sic] this light made up of ?

This video by Branch Education (on YouTube or Nebula) is a high level explanation of every step in a semiconductor fab. It doesn’t go over the details of how semiconductor junctions work, though. That sort of device physics is discussed in this YouTube video by Ben Eater, “how semiconductors work”

2 - How was program’s, OSs, Kernal [sic] etc loaded on CPU in early days when there were no additional computers to feed it those like today ?

When the CPU powers up, typically the very first thing it starts to execute is the bootloader. Bootloaders will vary depending on the system, and today’s modern Intel or AMD desktop machines boot very differently to their 1980s predecessor. However, since the IBM PC laid the foundation for how most computers booted up for a nearly four decades, it may be instructive to see how it worked in the 80s. This WikiBook on x86 bootloading should be valid for all 32-bit x86 targets, from the original 8086 to the i686. It may even be valid further, but UEFI started to take off, which changed everything into a more modern form.

But even before the 80s, computers could have a program/kernel/whatever loaded using magnetic tape, punch cards, or even by hand with physical switches, each representing one bit.

But how does the computer decode this binary “machine code” into instructions to perform? See this video by Ben Eater, explaining machine instructions for the MOS 6502 CPU (circa 1975). The age of the CPU is not important, but rather that by the 70s, the basics of CPU operations has already been laid down, and that CPU is easy to explain yet non-trivial.

3 - I get internet is light storing information but how ? Fookin HOW ?

The mechanics of light bouncing inside a fibre optic cable is well-explained in this YouTube video by engineerguy. But for an explanation of how ones-and-zeros get converted into light to be transmitted, that’s a bit more involved. I might just point you to the Wikipedia page for fibre optic communications.

How the data is encoded is important, as this has significant impact on bandwidth and data integrity, not just for light but for wireless RF transmission and wireline transmission. For wireless, this Branch Education video on Starlink (YouTube or Nebula) is instructive. And for wired, this Computerphile YouTube video on ADSL covers the challenges faced.

Quite frankly, I might just recommend the entirety of the Computerphile channel, particularly their back catalogue when they laid down computer fundamentals.

4 - How did it all come to be like it is today and ist it possible for one human to even learn how it all works or are we just limited one or two things ? Like cab we only know how to program or how to make hardware but not both or all ?

As of 2024, the field is enormous, to the point that a CompSci degree necessarily has to be focused on a specific concentration. But that doesn’t necessarily mean the hard stuff like device physics are off-limits, leaving just stuff like software and AI. Sam Zeloof has been making homemade microchips, devising his own semiconductor process and posting it on YouTube..

Specifically to your question about either software or hardware, the specialty of embedded software engineering requires skills with low-level software or firmware, as well as dealing with substantial hardware-specific details. People that write drivers or libraries for new hardware require skills from both regimes, being the bridge between Electrical Engineers that design the hardware, and software developers that utilize the hardware.

Likewise, developers for high performance computers need to know the hardware inside-out, to have any chance of extracting every last bit (pun intended) of speed. However, these developers tend to rely upon documentation such as data sheets, rather than having to be keenly aware of how the hardware was manufactured. Some level of logical abstraction is necessary to tractably understand today’s necessarily large and complex systems.

5 - Do we have to join Intel first or something to learn how most of the things work lol ?

Nope! Often, you can look to existing references, such as Linux source code, to provide a peek at what complexities exist in today’s machines. I say that, but the Linux kernel is truly a monster, not because it’s badly written, but because they willingly take code to support every single bleeding platform that people are willing to author code for. And that means lots and lots of edge cases; there’s no such thing as a “standard” computer. X86 might be the closest to a “standard” but Intel has never quite been consistent across that architecture’s existence. And ARM and RISC-V are on the rise, in any case.

Perhaps what’s most important is to develop strong foundations to build on. Have a cursory understanding of computing, networking, storage, wireless, software licenses, encryption, video encoding/decoding, UI/UX, graphics, services, containers, data and statistical analysis, and data exchange formats. But then pick one and focus on it, seeing how it interacts with other parts of the computing world.

Growing up, I had an interest in IT and computer maintenance. Then it evolved into writing websites. Then into writing C++ software. Right before university, I started playing around with the Arduino’s Atmel 328p CPU directly, and so I entered uni as a Computer Engineer, hoping to do both software and hardware.

The space is huge, so start somewhere that interests you. From the examples above, I think online videos are a fantastic resource, but so can blog posts written by engineers at major companies, as can talks at conferences, as can sitting in at university courses.

Good luck and good studies!