I’ve had a quick look at your model but I don’t have time to fully pull it apart.
I’m not an expert on dynamic components but I do make them and come from a background of advanced parametrics in other programs.
As far as I can see the large file size is due to your use of hidden geometry rather than parametric geometry. For example you appear to have three toplites above the door that are all essentially the same geometry but with different sizes or locations.
It is conceivable that one set of geometry can achieve all three iterations of the toplite cutting the size of that part of the model by about a third.
You can achieve this by using IF AND OR formulas that will assign different length dimensions or position locations to geometry depending on what list selection or dimensions the user inputs.
As for the best place to learn I mainly used the sketchup help website with the example models you can download from the sketchup warehouse. But as I said I have an understanding of parametrics so for me it was more of a “how do I do this specific thing in sketchup” rather than “what the hell is this”.
I’ve attached a basic dividable window frame that I built for concept design for you to play with.
Note how its construction makes if fully scalable with the scale tool, meaning you can change its size quickly without having to input the dimensions into the dynamic components window. While you may not need to dynamically scale your door component, a similar construction method to this model will allow you to create a parametric toplite and cut the file size down as outlined above.
If you have any specific questions let me know. I will try to check in tomorrow sometime.
BS CP - Window - Multiple.skp (86.3 KB)