Which Apple Pencil should I get for my 11th generation iPad?

The current iPad (A16) - sometimes and incorrectly referenced as iPad 11 - supports the first generation Apple Pencil and the USB-C Pencil.

For clarity and avoidance of doubt, this iPad (A16) does not support the second generation Pencil or Apple Pencil Pro.

Apple's definitive compatibility list for Apple Pencil and iPad can be found here:

Apple Pencil compatibility - Apple Support

their product pages list compatible devices

Apple Pencil - Apple

Your Apple iPad is compatible with the Apple Pencil (First Gen as well as second gen) and the Apple pencil (USB-C).