My idea is to create mounting pcb for esp32-c3-mini-1u with Neopixel leds, 5v and 3.3v regulator on it.
The 5v regulator will supply the Neopixel and feed into 3.3v to power the esp32.
I have a silly question. If I want to use a usb phone charger to power the project, would that not cause an issue due to some phone chargers providing regulated 5v and when you insert 5v into a 5v regulator you not going to get out 5v.
I know that there are fast chargers and phone chargers with higher voltages but some chargers or computer usb port give out a regulated 5v. Surely this will not be enough for the on-board pcb regulator.
Should I instead for go for a buckboost 5v convert.
I want to be able to plug usb cable into any usb charger. Some usb phone chargers as you know has higher voltage and some fast chargers ramp up the voltage to boost charge.
You have not yet thought this through. Come back when you have picked an appropriate power supply for the project. It should be rated for 2X the maximum anticipated current draw.
I believe the PD spec says the default state is 5V with a 900mA current limit. Anything above that has to be negotiated. And anything that delivers power via a USB connector should be 5V. So it doesn't seem like you need a 5V regulator.
Not to worry. I managed to figure it out already. I will have a custom psu made by Chinese company on Alibaba I used before. I just received an customer order of 123 units to do so I didn't have much time to do testing with usb phone chargers and regulators.
Fixed custom psu is better as the end.
I'll order 500 psu today because I will have more orders soon.