My iPad2 won't charge and needs activation
If the stock charger isnt working on the iPad, schedule a repair with Apple to get the battery tested for diagnostics and possibly replaced. You may have to pay if out of warranty.

As for activation lock-

You will need to remember the password. If you forgot the password, go to http://appleid.apple.com and choose "Forgot Apple ID or password" option below the sign in. It'll take you to http://iforgot.apple.com and then just add your apple ID email address and the captcha code. Once you hit continue (if it asks for a verification code then you need to check your other devices and see if you can get the code from a device that is signed into the same apple id). If you are already signed into the other device with the same account. Go to settings on the device, then your name (or iCloud then your name) and look for password and security. Once you find that, select change password. If you try to do it through the website it may have you go through account recovery, which takes some time before they let you reset your password.

(If it doesnt ask for a verification code then you'll need to choose reset password and ask to either send to email or answer security questions to reset the password.)

If you cant get the password for that account via either method then you'll need to provide Apple with a proof of purchase. You can either check your email for a receipt or contact your carrier/location where you purchased it. Without the receipt AppleCare can't help you.

If you bought the iPad from someone else and they are logged in, then you need to contact them and have them sign in (or reset their password to sign in via the methods mentioned above.)