DIY hair lightening/dye

Okay, so back in December I bought a box of Splat in Lusty Lavender (Yes, I've heard how terrible Splat is) and used the entire kit (bleach and dye). Well...none of it went well and I redyed it after a couple weeks which it did turn out right after. My friend helped me do it and I've been reading up on how to properly bleach since we started at my roots (that was probably our first mistake) but it came out patchy too. We were both hesitant about doing it so nerves probably didn't help us and I was very adamant about it not touching my scalp/skin and just being a freak lol anyway I plan on using Manic Panic this time for my color and possibly their bleaching kit. My hair has now faded into a dark magenta, people keep asking if my hairs pink at this point, and I have 1.5 - 2 inches of new growth that is my natural dark brown color. Do I still start at the ends? How do I make sure its even?

I apologize to any hair stylists reading this and going "oh no baby what is you doing" I know, I know I'm a terrible person.