I put all the files in the correct place. But they show up funny. How can I install them using the admin menu? None of them came with the tar.gz/.tar files

I think you're getting confused between themes and templates. Read the FAQ for a better explanation of the difference between the two.

Basically, in most cases you won't need to upload a template UNLESS THE THEME YOU CHOOSE SPECIFICALLY REQUIRES IT. In this case the theme will either mention that it needs a special template, and/or the template will be included WITH the theme.

For themes, the procedure is:
1) Download the chosen theme to your computer.
2) Unzip the theme to a place where you can find it.
3) Upload the theme FOLDER including all the files inside it to your XOOPS site to the /themes folder via FTP or similar. Don't rename the folder or it will result in a blank page.
4) Go to your amin menu and select the theme to include it in the theme selector block. Don't forget to make the theme selector block visible if it isn't already.
5) You may have to log out and back in again for the theme to show up if you've selected it as the default theme.

I think there should be an easier way of uploading themes via the admin section, like you do with templates :)

yay. thank you so much. Best explanation i've had yet. your my hero