Hi Manuel Marcus,
I am Dave, I will help you with this.
1
Bring up the on-screen keyboard, are the Shift and CapsLock keys working on that keyboard?
If you have access to an external keyboard, connect that to your laptop, are the keys working on that keyboard?
If the keys are working on both of them, then your laptop keyboard is faulty and it needs to be replaced.
2
Otherwise, please use these steps:
Open the Settings App
Go to System - Troubleshoot
Click Other Troubleshooters
Run the Keyboard troubleshooter
If that does not resolve this for you
Open Device Manager
Expand the Keyboards section
Right click your keyboard and choose 'Uninstall'
Then restart your laptop.