Recommend me some tutorials!

Hello, I'm a new hacker! :3 And by "new" I mean... Well, I basically lack any knowledge, other than map editing and very basic scripting. xD
I have a project in mind, but a few questions arose before I could even start working, so I need to know if the things I want to do are possible. If they are, I'd like some links to helpful tutorials to related topics and, if not, maybe an easier alternative and again more tutorials? xD

These are the features I'd like to implement:

- The character's decissions affect the storyline, like in one of those dating sims.
- When you talk to an important character, their image appears
- Pokemon sprites can be wider than the usual gba sprites ( I have some fakemon designed that don't fit in a very small space. I don't mind if the Hp box covers them a little.)

This I know can be done but I don't know how to do them myself (need tutorials):

- Changing the introduction text
- Creating/removing events

for tutorials, there's probably a fair few on youtube.

as for the things you want to implement ive seen them in other hacks and fangames.

the "choices affect the game" thing has been done in Reborn and Ruby Destiny: Life of Guardians (that particular hack had 3 seperate Paths)

the "Trainer portrait" thing i've seen in several hacks though i dont remember specifics off the top of my head, i think Victory Fire or Resolute did it though.

Expanding battle sprites shouldnt be too hard considering the amount of fakemon and alternate formes in some hacks.

that's the info i know from years of playing the hacks. i hope someone else can point you in the direction of actually creating one