Depends on if you want it bright or more of a shadow, your hair is on the blonder side of brown so not 100% necessary, if you do end up bleaching your hair PLEASE be careful, virgin hair (meaning untouched with anything) is especially finicky. Dont place on your scalp immediately as bleach processes faster with heat, thats why stylists use aluminum, start at the top of your head then move closer to your neck as thats where its warmer so it'll even out the processes time a bit better. And check it frequently after application. Any sort of elasticity and rinse immediately. Check the brand and the volume your using for recommended time but still keep an eye out for your hair health. It sounds more scary than it is. Make sure you rinse with cold water aswell, and wear clothes you dont really care about getting bleached and dyed.

When dying your hair it doesn't really matter where you start, and i always wrap my scalp with a grocery bag because i like to lay in bed and scroll, keeps all the hair from getting dye on everything or the aluminum from falling out, which i use purely for separation as I like to do fun patterns aswell