I've lost my phone
I need to replace my iPhone and don't know where to start
Question marked as
Do you want to try to find it, or just get a new phone?
If you enabled Find My on it before it was lost open a web browser to https://icloud.com/find and click on it, put it in Lost mode.
If it does not have Find My enabled you will have to look for it the old-fashioned way.
If you want to replace it, first see if any insurance you have will cover it. Then go to https://www.apple.com/iphone/ and choose from the available phones. Although Apple is announcing something this Tuesday (September 15) so it might be worth waiting a few days to see if there are more phone options.