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

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

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.