Can I just overwrite?

Can I just overwrite a "virgin" install of 1.3.0.1 ( installed via Fantastico), with the latest version? I've looked at both the Manual Install FAQ, and the upgrade FAQ, and they just scare the patootie out of me.......so I though I'd see if it's possible to do it this way instead.

If you have nothing in your present installation ( no changes that you would like to keep), best thing is to overwrite it with the new version. That way, you install like the first time, no file to compare etc.
Good luck

As E. Dravie said, if you have't made any changes to anything, yes, you can just overwrite the existing installation with the latest. Once you upload everything, just run zc_install. If you've set up your own template, you may have to tweak it to get it to work with the latest version.

Personally ... if you haven't made changes to anything ...

Why not just start fresh with Zen Cart v1.37 from the Downloads link at the top of your screen?

Then you do not have extra files, etc. that might have been removed ...

Just empty your database ... and start fresh ...