Assuming you’re using FEbuilderGBA
Creating a Chapter in 16 Minutes
Official FEBuilderGBA Thread where you can get help with any problems/bugs you run into.
There’s also a discord, with an FEBuilder help channel where you can get help quicker, and in real time.
For assets, such as portraits, the repo would be a good place to look:
For splicing, I would recommend just searching “Splicing” here on the site, you’ll find a good few tutorials for it. There’s also a channel for portraits and such in the discord, known as spritans, same goes for music if needed.