Before creating a new account, try to retrieve the old one. Go to http://iforgot.apple.com to retrieve your ID. Then go to https://getsupport.apple.com . Click 'See all products and services', then 'Apple ID', then 'Forgot Security Questions'.
If you really need to create a new ID go to http://appleid.apple.com and click 'Create your Apple ID'. You will need a different email address to what you have used before to be the ID.
I assume that by 'needs Activation Lock' you mean you want to be able to set it, not to unlock it? - To unlock it you will need the ID and password which were used to lock it. Getting a new ID won't do it.