Can't find css for panel and image sizing

Preface this by saying, I am VERY new at WP and writing css

I have installed NextGen Gallery and its [sub-app?] Galleryview

both programs are functional and I can get a galleryview style template by putting in [nggallery id=3 template=”galleryview”]

Now, the presentation of what shows up is what I want to change.

1. I want to make the whole panel bigger but can’t physically find that part of the code for galleryview.

2. My featured image is completely blown out of proportion and zoomed in

3. I thought I changed the size of thumbnails but it turns out not. where is this piece of code?

to be able to find where to add changes I really need either a flow style [eg. plugins->galleryview->editor->…………..] or an url [eg. galleryview2/view/gallery-galleryview.php] and what line to put it under

PS. I went to the gallerview site and chose ‘create a gallery’ [https://spaceforaname.com/galleryview/gallery-creator.html]
where I make one to look like what I want and it generated this:

$(‘#myGallery’).galleryView({
frame_width: 120,
frame_height: 120,
});

…but I have no clue where that would go, and if I am supposed to change ‘myGallery’ to be a keyword, or name of my gallery ID or what

thank you for your help!! sorry I’m still incompetent at this ??

https://www.ads-software.com/extend/plugins/nextgen-gallery/