New here from FL with a few questions

[Coastie]

1. What are the differences between Linux Lite, Peppermint 7 and MX-16?

Here are "unbiased" summaries from http://distrowatch.com/

Linux Lite is a beginner-friendly Linux distribution based on Ubuntu's long-term support (LTS) release and featuring the Xfce desktop. Linux Lite primarily targets Windows users. It aims to provide a complete set of applications to assist users with their everyday computing needs, including a full office suite, media players and other essential daily software.

• OS Type: Linux
  
• Based on: Debian, Ubuntu (LTS)
  
• Origin: New Zealand
  
• Architecture: i386, x86_64
  
• Desktop: Xfce
  
• Category: Beginners, Desktop, Live Medium
  
• Release Model: Fixed
  

Peppermint OS is a Lubuntu-based Linux distribution that aims to be lightning fast and easy on system resources. By employing Ice, Peppermint integrates seamlessly with Cloud and web-based applications. The distribution's other features include automatic updates, easy step-by-step installation, sleek and user-friendly interface, and increased mobility by integrating directly with Cloud-based applications.

• OS Type: Linux
  
• Based on: Debian, Lubuntu
  
• Origin: United Kingdom
  
• Architecture: i386, x86_64
  
• Desktop: LXDE
  
• Category: Desktop, Live Medium, Netbooks
  
• Release Model: Fixed
  
  
  

MX Linux, a desktop-oriented Linux distribution based on Debian's "stable" branch, is a cooperative venture between the antiX and former MEPIS Linux communities. Using Xfce as the default desktop, it is a mid-weight operating system designed to combine an elegant and efficient desktop with simple configuration, high stability, solid performance and medium-sized footprint.

• OS Type: Linux
  
• Based on: Debian (Stable), antiX
  
• Origin: Greece
  
• Architecture: i386, x86_64
  
• Desktop: Xfce
  
• Category: Live Medium, Desktop
  
• Release Model: Fixed
  

For my biased two cents, I have used Linux Lite for years and there are multiple reasons posted on this forum by me and others; MX Linux is a great distro is you prefer one based on Debian instead of Ubuntu; but I do not like Peppermint,  Lubuntu, or LXDE.

2. ... I'd have to disable UEFI on the computer for Linux lite to work correct?

That is what I did when I installed Linux Lite on my new computer and wiped out Windows.

3. Would I be able to print from a Canon MG 7720 printer or not since the computer is old?

Give Linux Lite a test drive on a live DVD or USB stick and see it you can print.