No charger to fit my usb plug in my new iPhone SE - what to do???

if you mean that the cable that came with your iphone se has a usb-c connector and you do not own a charger with an usb-c connector then you can do the following

1. get an usb-a cable or reuse an older ios usb-a cable
2. get a new ac charger with an usb-c connector
3. use an usb-c to usb-a converter

Apple hasn't included adapters in the box with phones for the last year. What comes in the box is clearly stated on their webpage.

you can let them know using their feedback channel Feedback - iPhone - Apple