Hi there,
If you've checked your coolant fluid levels (including the reserve), and changed out the thermostat, and the vehicle is still overheating that fast, then I think you've already determined if the water pump is working.
If this is a new key then it isn't a perfect cut, you will have to force it past the tumblers that it is binding on. Grab the key with a pliers, as you turn the key, wiggle it, push it in and pull it out as you turn it. Do not break the key off, but it needs to be forced. It may take a little while but it should work. Good luck.
Enter the security code in the radio. The code is a 5 digit number and should be written in the owner's manual or on a little label inside the glove box. If it still doesn't work after entering the code,check the fuses.
Go to your Honda dealer and purchase the factory service manual, it has the best info available for any repair you need to do, with the instructions for a proper repair. Have you tried looking at YouTube videos, or sometimes there are forums with some info, but neither is a great idea and can get you into more trouble than help you out. Stick with the designers of the car, they know what they are doing.
This sound silly, but look in the glovebox for a sticker with the code on it. Or in the manuals that came with the vehicle. It's a 5 digit number usually.
I had a similar problem, where the doors would not unlock with remote and opening with the key also was difficult. I had to hold the key turned to open the door. I removed the switches and the inside panel (see Chilton manual for instructions, also look at the sitess of Honda dealers that sell parts. They have exploded views that will help you ). Then I manually operated the wire connected to the lock post and noticed that the mechanism in the actual lock body was sticky and not operating freely. I sprayed this heavily with wd40 while manually operating the mechanism. Once it was operating freely I let it sit for a while and tested with the remote to make sure it was working ok. Then sprayed it with silicone spray lubricant. It has been working great for last two years and has had no problems. Hope this helps.