You can find information about charging your Pencil here:
Charge your Apple Pencil and check the battery - Apple Support
A second generation Pencil can only be charged using inductive (wireless) charging from a compatible model iPad or iPad Pro. If necessary, verify that your Apple Pencil is compatible with your iPad:
Apple Pencil compatibility - Apple Support
Assuming that you have an Apple Pencil that is compatible with your iPad, this support page may be helpful with pairing and use of the Pencil with your iPad:
Connect Apple Pencil with your iPad - Apple Support
If you continue experience any difficulties, here is one of the better troubleshooting guides:
https://appletoolbox.com/apple-pencil-not-working-heres-our-troubleshooting-guide/