Let’s see… use the Arduino IDE, plug it in via USB, and press Upload. Your program starts on boot, every time, reliably and quickly.
OR buy an SD card, learn what the heck “writing images” is, find a spare keyboard and monitor so you can see the RPi, learn how to use Linux for your first time, figure out how to copy files between your Macbook and Linux, figure out how to setup Wi-Fi, figure out how to run a program, then restart your RPi to find that your program didn’t start on its own, then figure out the million different ways in Linux to start a program on boot, only to find it takes forever before your program starts when you plug the RPi back in, then it turns out Linux screws up your timings so your LED art project doesn’t even work…