You can download Gentoo on this page-
This is what you want if your computer is 64-bit.
"install-amd64-minimal-20130816.iso" Which is a raw CD image 195 MB (minimal install)
32-bit is farther down the page.
I found out that unlike other distros, Gentoo Linux has an advanced package management system called Portage. I do not know this package management system. I also found out a little more: Gentoo does not, by default, use binary packages as other package management systems do (like RPM)-
In honesty I do not know that package management system so I wouldn't be of much help.
I see where being a Pastor, father and husband takes up a lot of your time and you wouldn't have the time to learn a new package management system, muchless write shell scripts and etc.
If your not sure what architicture your computer is you can run this command to find out-
After you download the iso image of Gentoo (or another distro) than all you would have to do is burn the .iso image to a CD/DVD.
I can dual boot just about any Linux distro out there, except for that one.
Unless you have to contend with the UEFI Windows 8 secure boot stuff- (all depends on your computer's motherboard and BIOS) The "lspci"
command is good for finding out that information-
Elementary OS Luna is a nice distro too if you would like to view it.
A friend of mine is running Elementary and he is very pleased with it. He mentioned that it's good for everyday use. My friend reccomends it-
Elementary uses the same sudo commands as Ubuntu so you should be at home with that.
Since your already running Ubuntu Elementary OS should provide you with ease.
Whatever you decide I'm here to answer your questions and provide you with assistance.