How can I tell if everything on my phone is backed up before I install a new sim card

Check the last backup date in iCloud, or manually run a local backup to a Mac or Windows computer.

I’ve never seen nor even heard of a report of issues with a SIM swap.

Locate backups of your iPhone, iPad, and iPod touch - Apple Support

How to back up your iPhone, iPad, and iPod touch with iCloud - Apple Support

What does iCloud back up? - Apple Support

Manage your iCloud storage - Apple Support (also shows how to find and check backups)

Dairyproducts2020 wrote:

OK how on my phone do I get to iCloud

Through a cellular or Wi-Fi or MiFi connection, usually.

You will be able to back up to iCloud over Wi-Fi, or 5G cellular if your iPhone and your carrier both support 5G.

iCloud backups are not available on 4G and earlier cellular connections.

Details on ➡️ How to back up your iPhone, iPad, and iPod touch with iCloud - Apple Support

Iphones don't store anything on the SIM card.

What is it you think you are going to lose by removing the SIM card?

The blue-colored text here is a link to more information.

Tap on those blue-colored links (from my previous reply here), and learn more about how to do what you want.

I’ve linked to how to check iCloud.

It seems clear you’re not using a Mac or Windows system for backups now, so you’ll have no existing backups there.

Dairyproducts2020 wrote:

If I change my phone service to another company which I have is there a way I can get my own personal hotspot or Wi-Fi

Your iPhone must be not be carrier locked by your current carrier, and your new carrier must offer the hotspot feature, or offer MiFi or Wi-Fi device.

Here is ➡️ How to unlock your iPhone for use with a different carrier - Apple Support