Delete and reinstall to return compile to default?

I am a Scrivener novice, that is, I have written extensively in Scrivener 2, but only lately have begun to explore compile in Scrivener 3. And it is making a mess of things. When I began with the default settings, it was fine. Now I changed settings and my pdf doc has different font settings and sizes, different spaces, and all other kinds of hoopla. I just want to get back to the original defaults. Should I delete the whole schemer and reinstall to get it back. Thanks!

Scrivener’s default compile formats can’t be overwritten. Only duplicated and edited. So the default compiles will always be available to you.

My problem is that I have assigned section layouts and the outcomes are a disaster. I have spent the last several hours trying to adjust, but to no avail. I cannot figure out how to get the results I want. For example: the front matter and contents page do not have a page break before and the simple word “Contents” above a single page that lists the TOC. (My Copy Documents to TOC did not format page numbers in the TOC, too, but that will be another post after I figure out the compile).

I get it that all I need to do is set it up once and I will be set for all genre (novels, non-fiction, etc.). I had some time today to work on this, but have nothing to show for the hours spent.

Thanks for your input.