Please help me

Good afternoon sujan146,

Welcome to the Apple Support Communities!

I understand you have created a new Apple ID on your iPhone and want to download music to it. Do you have an Apple Music subscription? If you wish to use a different Apple ID, it is best to change your current Apple ID rather than create a new one. You cannot merge purchases made on different Apple ID accounts.

If you have created a new Apple ID instead of changing the previous one, then you will need to sign out of the iTunes and App store and sign in with your new Apple ID.

I'll include some resources here to help you with this:

Change your Apple ID

What to do after you change your Apple ID or password 

Create, manage, and use an Apple ID

Sign in to the App Store and iTunes Store on your iPhone, iPad, iPod touch, Mac, PC, or Apple TV

Manage your Apple Music subscription

Please provide some additional information regarding what you are trying to accomplish, and I'll do my best to help you!

Take care.