i am facing difficulty while updating apps through app store. When i tap the update button, it asks me to sign in with itune store and box appears to write my password. I write the password and it shows a meesage that apple id or password is incorrect.
This very well may be your problem. See What to do when the Mac App Store shows a different Apple ID for software updates https://www.macworld.com/article/3267709/mac-app-store-apple-id.html. This document refers to a prior owner, but is also applies to cases where a current owner's old Apple ID is the problem.
Basically, If an app is purchased/downloaded using one Apple ID, then you can't update it with another Apple ID. The app is inextricably linked to the first Apple ID. You'll have to delete it and repurchase/download it again with the second Apple ID.
This very well may be your problem. See What to do when the Mac App Store shows a different Apple ID for software updates https://www.macworld.com/article/3267709/mac-app-store-apple-id.html. This document refers to a prior owner, but is also applies to cases where a current owner's old Apple ID is the problem.
Basically, If an app is purchased/downloaded using one Apple ID, then you can't update it with another Apple ID. The app is inextricably linked to the first Apple ID. You'll have to delete it and repurchase/download it again with the second Apple ID.
If you are locked out of your Apple ID account you can go to https://iforgot.apple.com
This will provide you with the recovery steps you put in place for this situation.
Here are some support articles that should help:
If you forgot your Apple ID password - Apple Support
If you forgot the answers to your Apple ID security questions - Apple Support
If your Apple ID has been locked or disabled – Apple Support
Can’t update my apps
