Can't get updates on Mac OSX 10.5.8
I have a Mac version 10.5.8. A year and a half ago I stopped getting software updates. How can I start getting them again? Whenever I do the check, the updater tells me there are no updates. I know there must be. How can I get around this? I think it has something to do with Firefox no longer being "safe." I just switched to Safari, but still no updates. Help. I can't get latest versions of Java that I need for some banking needs.
MacBook, Mac OS X (10.5.8)