Sounds like the battery is running low for the key issue with the alarm going off. The battery should charge when in the slot but may be past recovery if it’s not taking a charge over the next 2 days you have it and a new battery will be needed.

I assume you’ve went into the sub menu and done a tyre reset? This should clear any faults. The system can be a bit sensitive if it’s been sitting and tyre pressures have dropped and then inflated again.