How to made a new account on iPhone without deleting older account?plz guide me.

See If you forgot your Apple ID password https://support.apple.com/en-us/HT201487

You also can use Having trouble signing in/iForgot https://iforgot.apple.com/password/verify/appleid to try to recover it.

And you may need to see If you forgot the answers to your Apple ID security questions https://support.apple.com/en-us/HT201485

Before trying to answer your security questions is very important that you think about your questions, including your birth date, and their answers carefully and try to recall all details you can. If you don't answer them correctly enough, then you easily can lose control of your account.

Note that If you're using two-factor authentication and can’t recover your password, you usually will need to enter account recovery. See Recover your Apple ID when you can’t reset your password  https://support.apple.com/en-us/HT204921

And, in general, if things go badly using the above links, you will need to try to recover your account if you want to use it again. Again, see Recover your Apple ID when you can’t reset your password https://support.apple.com/en-us/HT204921 Use this link to request account recovery to regain access to your account.

Apple ID - create a new.      

Apple ID – Create         

Family Sharing.         

Family Sharing - Set up.        

When changing to the new ID, there may be some data loss, but you can minimize it. If syncing photos with iCloud, ensure Optimization is turned off in Settings/Your Name/iCloud/Photos and/or in Photos/Preferences/iCloud. Then make sure full resolution photos are on the device/computer. When signing out of iCloud, if asked whether you want to retain data, choose yes. Messages conversations will be lost if they are addressed to the ID. See the article below for other places that the old ID should be removed. See Winston Churchill's response in the below discussion. Also set up Family Sharing between the IDs to keep access to your apps/purchases. 

How to switch Apple IDs on your iPhone or iPad.      

How to transfer all files from one iCloud account to another.        

What to do after you change your Apple ID or password - Apple Support.     

I share my wife’s account but now I have an Apple Watch and I need to create a new account to pair my watch