newbie 2 questions

Hi Caroline
am new to the wordpress world so forgive my probably stupid question.
I really love Spun and really want to use it for my website.
However I would like to modify a few things and have searched through this forum and it sounds like I should create a child theme before changing anything. I have read up on how to do this but
where can I find the style.css file for your theme as it does not appear in my FTP file manager. Am I blind?

Also can I achieve the following with your theme? I hope so ??
a) I want to have an initial frontpage (first page people see when they go on my website)to just have circular images and no text. I’d like all but one of the images to be fixed (not clickable). The one that can be clicked on will redirect people to the next page which will act like a home page with page menu at the top right

many thanks for any help
polly