point me in the right direction to learn to build a multi page, midi controlled drum step sequencer.

Hi, I am a total beginner with Max. I've poked around some tutorials and now understand how to use help and reference to learn stuff. I'm looking for advice on what to learn to achieve the following:

I want to build a M4L device that uses my 2 Xone K2 controllers bottom section, an 8 x 4 grid of led buttons that send/receive midi notes, to control a 4 note XOX style drum sequencer.

The basic idea is that i want the grid of led buttons to display/edit a 32 step long sequence, and i want to be able to switch between edit/display for 4 different notes.

Once i get that figured out, I want to be able to edit individual notes in the sequence with push encoders. The idea is that the push encoder when turned displays a value, and when i push the encoder and one of the steps it applies that value to the step.

I want one to set velocities (maybe pick from a range of 5 or 6 set velocities rather than the full 0 - 127)

one to set a % chance of the step playing

one to set "play nth of x2bars"

one to set flam/roll for the step

The controller's led button grid can display red, orange, or green leds based on what midi note it receives. I'm hoping i can use some combination of different colors, maybe blinking to display what kind of information is on each step, and also have running lights to show the sequence position.

currently i have no idea where to start.

Can you recommend what particular objects i should be looking at, and devices i can check out that already do some of this?

I understand a bit of JavaScript if that's helpful at all. Should I be looking at writing js and doing this as midi clip based via the LOM as that would be a more familiar process to me?

Thanks