1
For the Bitlocker Recovery Key problem:
If your drive is encrypted with Bitlocker, the only place the Bitlocker Recovery key is automatically stored is on the associated Microsoft account on the link below, be sure to check any Microsoft account that may have been used on the PC and also any work or school account that may be linked to the PC.
https://account.microsoft.com/devices/recoverykey
Are you able to find the Bitlocker Recovery Key on any account that may have been used or linked to the laptop?
If not, do you have a safe backup of your files, or use a cloud service like OneDrive to sync your files online.
2
For the boot problem, are you able to force your PC into the recovery Environment using these steps.
Start your PC, just as Windows attempts to load (spinning dots), press and hold Power Button for 5 - 10 seconds to perform a Hard Shut Down
Do this twice
On the third start Windows will boot into the Recovery Environment and from there you can access System Repair, Safe Mode, Command Prompt... etc.