Can't Download Apps onto my Iphone 13

It sounds like you have poor connectivity to the Internet.

Connect to Wi-Fi on your iPhone, iPad, or iPod touch - Apple Support

 Connect to a Wi-Fi network

1. From your Home screen, go to Settings > Wi-Fi.

2. Turn on Wi-Fi. Your device will automatically search for available Wi-Fi networks.

3. Tap the name of the Wi-Fi network that you want to join. Before you can join the network, you might be asked to enter the network's password or agree to terms and conditions [ Use captive Wi-Fi networks on your iPhone or iPad - Apple Support ].

If your iPhone or iPad won’t connect to a Wi-Fi network, or if you have related connectivity issues, read this support article --> If your iPhone or iPad won't connect to a Wi-Fi network - Apple Support

Try restarting your device.

Refer to this page for Apple Support features ➔ Contact - Official Apple Support

Select from the presented options until you find a solution for your issue, or see if there is a chat or phone call contact method offered lower on the page (you sometimes have to narrow down the options multiple times before this is shown). If you do not see your issue, keep experimenting with any series of selections until you reach one that offers a chat session or a telephone call and get the representative to redirect you.

This support article has various country telephone numbers for contacting Apple for support and service ➔ Contact Apple for support and service - Apple Support