iTunes sharing

You can share your music library from a computer with other Family Members using Home Sharing. This is entirely independent of Family Sharing.

Link-> Use Home Sharing to share media from a computer to other devices - Apple Support

You cannot share music directly over Family Sharing unless you have an Apple Music subscription, in which case you can share that subscription, but not your actual music library.

You can share music purchased from the iTunes Store over Family sharing without an Apple Music subscription: link-> How to download apps and content that your family members purchased - Apple Support

I have my old iTunes account from I would like to share my music with my family.

You are sign in here .  .  .  with your Apple ID & Password.

Your Apple ID is the personal account you use with all Apple products and services. It includes the email address and password you use to sign in, as well as the contact, payment, and security details that you use with Apple.

You can’t merge multiple Apple ID accounts.

Do I need to pay for an iCloud account for that purpose?

Yes, see the following Apple articles:

Set up Family Sharing

Set up Family Sharing - Apple Support

What is Family Sharing?

What is Family Sharing? - Apple Support

Make sure that each family member has a unique Apple ID

Make sure that each family member has a unique Apple ID - Apple Support

Download family members’ purchases on iPhone

Download family members’ purchases on iPhone – Apple Support (UK)

Add a family member to your subscriptions from Apple

Add a family member to your subscriptions from Apple – Apple Support (UK)

Share iCloud+ with your family

Share iCloud+ with your family - Apple Support

Use Family Sharing to share iTunes Store purchases on PC

Use Family Sharing to share iTunes Store purchases on PC - Apple Support (GE)

See this Apple article: Upgrade to iCloud+ -> Upgrade to iCloud+ - Apple Support

See also: iCloud+ plans and pricing -> iCloud+ plans and pricing - Apple Support

If you have upgraded iCloud storage, it would take about 1 to 3 business days in order to process.

Once your request for iCloud+ has been activated, you should receive an invoice in your email box.

If you have an iCloud subscription, you will receive a monthly bill from Apple, check your email box.

You pay monthly for iCloud storage.

I have my old iTunes account

1.

It depends on what you did with your 'old Apple ID'. If you have deleted it, it is no longer valid, it simply no longer exists and it no longer works.

To understand about a deleted Apple ID, see the Apple articles below:

How to delete your Apple ID account

How to delete your Apple ID account – Apple Support (UK)

Understand and control the personal information that you store with Apple

Understand and control the personal information that you store with Apple - Apple Support

2.

If you've ever requested to deactivate your Apple ID, see

See -> How to deactivate your Apple ID account

How to deactivate your Apple ID account – Apple Support (UK)

scroll to ⤵️

How to temporarily deactivate your Apple ID

Sign in with your Apple ID at privacy.apple.com on a Mac, PC, iPhone or iPad, and select "Request to deactivate your account". If you can’t see this option, it means that this feature is not available in your country or region. 

When you request to deactivate your account, you receive a unique alphanumeric access code. Make sure that you keep this access code in a safe place – you must have it to reactivate your account. 

After we verify that you are the account holder making the request, we deactivate your account.

Can I reactivate my account?

Yes. If you request account deactivation, you'll receive a unique alphanumeric access code. When you're ready to reactivate your Apple ID, contact Apple Support, provide your access code and we’ll help you reactivate your account. If you lose this code, we won't be able to help reactivate your account. 

3.

If you stil have / know that Apple ID, check your Apple ID via your email box, see this Apple article: If you forgot your Apple ID

If you forgot your Apple ID email address or phone number - Apple Support                  

OR see -> Having trouble signing in?

https://iforgot.apple.com/password/verify/appleid

Try this -> If you can't connect or sign in to iCloud

If you can't connect or sign in to iCloud - Apple Support

See also -> Contact Apple for help with Apple ID account security

Contact Apple for help with Apple ID account security - Apple Support