It keeps saying not connected to internet but i am

Check your WiFi Router / Modem for --> Recommended settings for Wi-Fi routers and access points ...

Connecting to Wifi is the first part and then getting connected to the Internet is the second

1. If you connect to Wifi, doesn't necessarily mean you are connected to the internet. If you are not connected to wifi could be a problem with iPhone settings or Router/Modem Settings
2. If you are not connected to the internet is the sole issue of Router / Modem Settings. Contact your ISP immediately

For your Internet connection.

• Over Cellular: contact your Carrier (Cellular Service Provider). The agency who issued the SIM to you
• Over WiFI: Contact your ISP (Internet Service Provider), the agency who provided the Internet Service on your Modem/Router to you

However --> Connect iPhone to the Internet - Apple Support

Don't worry about cellular, you cannot update your iOS over mobile data with an iPhone 11.

1. Make sure to follow what SravanKrA said about your WiFi connection.
2. Make sure you have at least a 50% battery charge and I suggest you connect it to power.
3. Take it out of low power mode.
4. Make sure you have at least 6GB of free space.
5. Turn off your VPN.