Just to make sure we understand the situation, your Clarity sat for two weeks unused, then when you tried to start it for the first time after two weeks is when you experienced all of the above problems. No problems prior to this?
You mentioned charging, I assume you mean that you used a 12V charger? Do you have some type of jump starter, either jumper cables or one of those jump start batteries? If you don't I recommend get a jump start battery, they are good to have anyways, the lithium ones are small and lightweight so you can keep it in the glovebox or in the storage bin in the trunk. They cost around $50.
I would try doing what I suggested in post #39 to Sky9ine, connect a jump starter, but don't try turning on the car, instead while you have the jump starter connected plug in the EVSE and see if you get a steady green light indicating that HV battery charging has started. Or if you use scheduled charging and just get a blinking green light then use the key fob to start charging. Once you get a steady green light you can then remove the jump starter and the green light should stay on. If it does then let it charge for a couple of hours. Use the HondaLink app to check SOC while it is charging. After a couple of hours of charging try starting the car and seeing if it is drivable. There may still be a couple of error messages but they should go away in the first mile of driving. If they don't or if the car is undriveable even after two hours of charging, your next step would be to either replace the 12V battery or have it towed to the dealer as it could be a larger problem not the 12V battery. What is the mileage and years on your Clarity?