Sine you're new to ROM hacking, I'll link you to some tools.
Somebody probably already did that. Whatever.
Tools for GBA ROM Hacking:
I don't wanna link the tools.
Pretty much makes ROM hacking 10x easier.
I don't miss FEditor Adv. Nobody does.
Fire Emblem ROM hacking is a very slow and tedious process, so you have to be very patient.
Fire Emblem is a very fragile game, so you will crash it... a lot.
And you're gonna have to get creative to get around the limitations.
And do not wait for FEXNA.
I think BwdYeti is the only that's working on it.
He had help, but his helpers just vanished.
So development with FEXNA is slow and he is also working FE7x.
A good way to boost your morale is by seeing some NSFW trap pics. ONLY TRAPS! Traps are bae.
Nightmare (or you can use Nightmare 2)
Nightmare is good for doing stuff that FEBuilder can't do.
Like assigning moving map sprites to a class. I can't figure out how to do it.
Along with some other little things.
Good for memory hex and stuff.
I still use this program because I'm used it and it feels very intuitive.
It's a good thing for events, adding stuff, and doing more complex things with eventing.
Where Do You Start?
You just mess around and play with stuff.
That's how I learned to ROM hack stuff.
I made random maps, inserted random map sprites and animations, constantly got frustrated with FEditor Adv, and I used Eventiel, but I spent most of that time messing around with generics (I love generics with high stats for some strange reason).
These videos will also help:
Creating Chapters in FEBuilderGBA:
Fire Emblem Eventing Tutorial (Single Take):
(I still find this video useful, I dunno about you.)
How Should You Design Levels In Fire Emblem?:
Sadly, I'm on my laptop, but MarkyJoe did make a Tiled tutorial.
I have the HTML version on my main computer.
Ghast did also make some hacking tutorials, but they're outdated.
Yes, I'm a MarkyJoe fangirl.
Okay, I'm getting bored writing this.
I probably wasted my time writing this. My grammar is pretty bad. Heh.
uses a smoke bomb to vanish