Electronic – Who is the CPU or FPGA maker in this picture

Yes, it's an opto. You can confirm by googling the part number and the word "datasheet": "LTV4N35 datasheet", and find the datasheet for the part. https://www.arrow.com/en/products/ltv-4n35/lite-on-technology

One of the pages in the datasheet will show the pinout:

If you're slightly lucky, the datasheet will even have examples of usage in a circuit and which external parts it needs connected to the pins (like resistors, clock crystal, capacitors, inductors, etc.)

I believe that is a 2-pin Molex "Mini-Fit Jr." nylon line plug

There are other, generic, manufacturers - but I'm providing a specific name brand as I don't see that any of the generic versions have a specific name. Searching for ATX style or EPS style may help.