Complete tutorial or docs for begginers

Hi, i’ve made a Qt/QML application and i want to create a snap package using snapcraft. Untill now, i’ve only created a snap package of a very simple python application following the tutorials and “trying” changes till it worked. However this is like a lot of magic to me, and now i’m not able to create a yaml file for my qt app. Is there any more comprehensive tutorial for creating snap package from scratch? All tutorials i’ve followed starts from an example project and i really can’t fully understand why the yaml file is written, i just try and try till it works.
This is my yaml file:

name: myapp # you probably want to 'snapcraft register ’
version: ‘0.1’ # just for humans, typically ‘1.2+git’ or ‘1.3.2’
summary: Very simple app # 79 char long summary
description: |
My description

grade: stable # must be ‘stable’ to release into candidate/stable channels
confinement: strict # use ‘strict’ once you have the right plugs and slots

    # See 'snapcraft plugins'
    plugin: qmake
    qt-version: qt5
    project-files: []
    source: src/
    install: |
      make install

      - qmlscene
      - libqt5qml5
      - libqt5gui5
      - libqt5serialport5
      - libqt5core5a
      - libqt5network5

    - qtdeclarative5-dev
    - qtbase5-dev

    command: myapp

After executing this, i get “myapp command not found” error after priming.