Neocities.org

first get yourself familiar with arduino and microcontrollers, as well as basic electronics. pretty much all of the "pretty lights" cosplays/wearables use these to control the lights. there are a lot of projects on hackaday.io so what i usually do is check if someone there has done anything similar so i can adapt what i can (it saves work in the long run).

my must-learn recommendation is to learn how to use batteries safely in wearables, this will probably be one of the harder things to learn, but wearables have them as a prerequisite.

my best piece of advice is to experiment, make mistakes and don't give up, as this should help to get you familiar with how things work (that being said, it kinda requires a moderate disposable income, so do what you can)