Just few pointers. The file size is way to big for 4 mins, win media is very flexible and good quality can be produced at smaller file sizes, this will come with practice.
When filming out of a window switch to manual focus otherwise as happened in your vid the camera focuses on the window instead of looking beyond it.
Capturing fireworks also switch to manual focus, and set the focus to something at about the same distance as the fireworks.
Your vid shows that you can do good stuff with free tools.