1.) How do i edit movement scripts
Learn basic scripting, and when you get enough practice you'll know what to do.
2.) How do i change trainers pokemon
Open your ROM in a hex editor and go to offset 039CC2. This is a list of all the trainers in the game: first is the name, then [50], and then any of the following four data structures:
[00]
[Level] [Pokemon] (up to 6 times, once for each Pokemon)
[FF]
[01]
[Level] [Pokemon] [Attack1] [Attack2] [Attack3] [Attack4] (up to 6 times, once for each Pokemon)
[FF]
[02]
[Level] [Pokemon] [Item] (up to 6 times, once for each Pokemon)
[FF]
[03]
[Level] [Pokemon] [Item] [Attack1] [Attack2] [Attack3] [Attack4] (up to 6 times, once for each Pokemon)
[FF]
If you want I can send you a list of what values represent each item and attack. For now, just know that "level" is the level in hexadecimal, and "pokemon" is the Pokemon's Pokedex number in hexadecimal.
3.) How do i create a new map using goldmaps
It's
much easier to overwrite existing maps than to create new ones. If you need to create a new one, you need strong knowledge of pointers and repointing.
4.) How do i edit the world map
The Johto Pokegear map is located at offset 091FFF in a hex editor, and Kanto is at offset 092168. Each 8x8 tile is represented by a byte. The first two rows of the map are normally covered by text in-game, so you won't see any changes unless you start changing bytes further down.
5.) Wow do i use unlz.gba
UNLZ-GBA is for GBA games, and not relevant to hacking Gold and Silver.