Version 1.4.4 wants to be current

The following information is required to get an answer:
Get this information from the PHP diagnostic (in the configuration wizard).
Gallery URL (optional but very useful): http://www.saltyseadog.net/photogallery
Gallery version: 1.4.4
Apache version: 1.3.41 (Unix)
PHP version (don't just say PHP 4, please): 5.2.5
Graphics Toolkit:
Operating system: Mac OSX 10.15
Web browser/version (if applicable):

I have an old gallery that I've been hanging onto, and I want to start using it again. I have a ton of photographs in it, and I don't want to lose it.

1. How can I back it up?

2. What version stops to I need to consider to upgrade to the latest?

3. Where can I find instructions to go with each upgrade?

4. What am I not considering?

Thanks

Drew