Go to the App Store in Settings and you can just sign out of your old ID and then create a new one. Do you already have a new email for this account? Any apps that you have already bought with this ID will need to be updated with it, so when updates are due you will need to sign out of the new one and then sign back in with the old ID.
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.
The Apple ID support link at the bottom will also (indirectly) take you to where you need to go to change your password.
You will need to log out, and back into pretty much every iStore on both the computer and iPad after you change your password; and email and iCloud if you use them.