You've probably heard this question many times before but I come to you in my time of need for you have great wisdom that I don't posses. No but seriously I don't know anything about tv's or cables or whatever. I will give many detailed pictures so you atleast know all the ports and stuff I have at hand. 

What I tried so far:
1) I've tried the cable of pic 1 and 2 in the area of pic 13 (this is my tv's av3 connection). I go to AV3 with my remote but it doesn't work. I do notice that when I turn the mega drive 2 on it does seem to respond in the way that my black screen lights up just a little bit more but it doesn't do anything else, no sound ether. Idk what this means but still

2) I've tried the weird sega cable thingy of pic 3 and 4 on pic 12 (specifically the one weird metal tube sticking out in the left low corner that's distant from the rest of all the weird cably inputs). I have put the weird sega box thingy that is on the cable to I and to G but nothing seems to work even if I go of every single AV or HDM etc... that my tv has to offer

4) I've also tried using the cable from pic 1 and 2 in pic 12 with all the colorful parts between the right side (PC input) and left side (HDMI input) my tv calls this 'components'. I do see the same slight light up when doing this and switching to aaid components channel altough this varies on how I plug the yellow, red and white one in. 

Questions I have:
Main question: how can I get this fixed/ working or is it over for me( I don't mind buying a cable because it's already a sunk cost now anyways)

Side questions: I am looking to learn the wisdom you have to offer me and these are some questions of the top of my head that may help me with likewise problems in the future.
-what are all my different cables called and why are they called that?
-is there a difference between my weird sega cable from pic 3/4 and my white, yellow, red cable from pic 1/2. What are their functions generally. Especially the sega box thingy, what does all of what's on there mean (like the I and G switch, what does I and G stand for and why is it there?). Why does this box have multiple ports and cables attached to it (if I can say it that way)?
-what is the reset button for on my sega megadrive 2?
-are my 2 controllers different. The one with grey start button feels way lighter then the one with the red one, why is this, is there a difference, did I buy the wrong controller? (I wanted 2 for streetfighter so I bought one extra which was the red start button one)

Side info not in pics/ deemed possibly irrelevant that you might want to know:
- the game currently injected is one of those 1 in 122 type games
- I also have sonic and knuckles 3 (I think it's 3 idk) which I do think is official so maybe this is relevant for reading (I put it in but nothing changed)
-I have a different power cable from the original sega masterdrive 2 and altough one of the forks to put it in the plug was cracked at the bottom I forced it back up and tried plugging it in, nothing exploded and the sega master drive 2 turned on without hazard (not on tv but the red light lit up on the console it self)

Other stuff:
-idk what type of tv I have but I think it's either PAl or nsc or whatever (I am aware these are like the only 2 types I just don't know which one it is, probably pal tho)

Outro: as you can see from my many questions I have no clue what I'm doing (my mom gave this to me because she knows I like retro stuff but this is the first time I've done retro console things). If possible explain the questions I have like I know absolutely nothing about it (so really think over terms like 'scart' or whatever that is and think 'would this dumb**s understand this?').  Anyways thank you in advance, feel free to share links  from cables I might need to buy but please tell me why I'd need to buy them. You can also download my images and draw circles around where I need to put certain things if that makes it easier for you (it would for me ngl). If you need more info you may ask I might be able to give it if I can even understand the question.

Thank you in advance :)

How do I connect my sega mega drive II