what is the problem with my apple id? because I can't re-download or update my apps on my iphone

You may need to have a payment method on file, even if the app you want to download is free.

Sign in to your Apple ID account page and edit / update your Apple ID details.

https://appleid.apple.com

On the Sidebar click Payment methods -> then tap Payments Methods and tap Manage payment method.

Or -> Change, add or remove Apple ID payment methods

Change, add or remove Apple ID payment methods – Apple Support (UK)

See also -> Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

You can also use your Apple ID balance as payment method:

Add money to your Apple ID balance

Add money to your Apple ID balance – Apple Support (UK)

What you can buy with your Apple Gift Card or Apple ID balance

What you can buy with your Apple Gift Card or Apple ID balance – Apple Support (UK)

How to redeem your Apple Gift Card or App Store & iTunes gift card

How to redeem your Apple Gift Card or App Store & iTunes gift card – Apple Support (UK)

See also -> Require a password for App Store and iTunes purchases

Require a password for App Store and iTunes purchases - Apple Support

Is your account disabled?

See the Apple Support article(s) below. 

If you see a message that says 'Your account has been disabled in the App Store and iTunes' - Apple Support.   *

Contact iTunes Support for assistance. See the Apple Support articles below for contact information.   

iTunes Support – world wide   -

Apple Support schedule phone call     -

Billings and Subscriptions   -

Apple on Twitter

If the account isn't disabled.

See the Apple Support article(s) below. 

Apps won’t downloaded.  *

ASC YouTube for what to do if you can’t make a purchase on your iPhone -

App Store, iTunes Store, or other Apple services - If you can't connect   *

Some things you can try. Do you have access to another WiFi network where you can try? That has worked for several people.

Try a restart.

Restart your iPhone, iPad, or iPod touch    *

Try a forced restart. See the section towards the end of the article.

Reset Device. -

If necessary

Hard reset.     -

Do a backup and try a factory reset. Then restore from the backup.

Restore to Factory setting.      *

Restore - If you see an error when you update or restore your iPhone, iPad, or iPod.   *

Backup - Restore your device from an iCloud or iTunes backup.