[Emerald] How to add a Setting menu at the start of new game?

[Nickosaur]

Hopefully this is the right way to ask/post
Hi I'm completely new to ROM hacks and the community and I wanna give myself a small project to work on.


Backstory: watching alpharad play mariomon I noticed there was a difficulty, nuzlock rule settings at the start of a new game. That little dialogue got me thinking of what I would like in a game


I would like to try:

- (priority) adding a dialogue box at the start of a new game that allows randomizes the pokemon or not
- -new set of randomize every new game start

- adding all Gen 1-3 to be catchable

- characters customization/ insert own sprites

- change time events into step requirements (ie. Berries grow based on steps similar to xp in day care)

- add new fairy typing and fairy moves to move pool and rebalance trainers (if needed)


I would like to have this mostly So I can run the ROM hack on my 3ds, and when I decide to do a new game have the pokemon randomize so I don't have to do a whole new patch on my computer every time.


Any good tutorials or guides I could reference to have any of these features added??

Thanks in advance!!