I have been recently been collecting parts from various machines that I could collect few micro-controllers. I have two questions:
The answer to these questions would be found in the datasheet.
Some chips are reprogrammable, some can only be programmed once, some have a "fuse" - you can reprogram them any number of times, until you "blow the fuse", at which point they are no longer programmable. I even have some (very old!) chips which you could program once, and to clear the programming, you expose the chip to ultra-violet light.
You describe the first chip as "Arduino IDE compatible" - that covers an awful lot of chips. If you know the specific chip, google the chip name and "datasheet". For example, googling "atmega328p datasheet" returns https://www.sparkfun.com/datasheets/Components/SMD/ATMega328.pdf as the first link. Datasheets take a bit of work to get used to, but (usually!) everything you need to know is in there - how much memory it has, how fast it runs, what all the machine code instructions are, what each pin does, how to wire it into a circuit, and how to program it.
I did a search for "WT62P2 datasheet", and it came up with https://www.digchip.com/datasheets/parts/datasheet/520/WT62P2-pdf.php This says that it's a 6502 processor (slightly modified) running at 6Mhz. 6502 processors are very well documented - many of the home computers used this in the 1980s, back when computers came with manuals on the secret innards of the hardware.
It is probably 5v, there's a pin marked "VDD +5V power supply".
The datasheet does not specify how to program it, but I see it has an i2c bus - if it were me, I'd power it up and try to connect to the i2c bus. Arduino has support for i2c.
It has one pin marked USB D+ and one USB D-, these are likely to be for send and received data. The 6502 didn't have any instructions to read/write data from other devices, instead it would do "address mapping" - there would be bytes of memory at specific addresses; reading the right address might give you a byte from the keyboard, or writing another byte might make the disk drive start to spin. I would expect this to be the same. If you have one that is already programmed, make sure you make a copy of the data that it has before changing anything - you can unassemble to code, to see what it is doing. It will take quite a bit of sleuthing. The datasheet is missing a lot of critical data.
If you have only the chip, to get it to do anything, you need to hook up VDD to 5V, GND to 0V, and a 12Mhz oscillator (not included) to the correct pins, with capacitors, in this layout: http://4.bp.blogspot.com/-0q_16rv2Wj0/ToJ0pvJbwlI/AAAAAAAAAJk/IE9yuSTi4Yk/s320/untitled1.PNG (but obviously with different pins).
Good luck!
