Upgrading Drupal

I'm upgrading from 5.5 to 5.7. Should this be as easy as just overwriting the core with the new files? Do I need to do anything else?

Recently I upgraded my Drupal 5.3 to 6.x, everything was going well then I started uploading the modules, and now I get the "page not found - The requested page cannot be found" . I made sure that I downloaded the right modules 6.x. My menus, blocks have all disappeared and I cannot log in using the user account. The default theme is still active,.

Alright, okay: leaving it for that long was shtoopid, but I had other things on my mind. That said, 4.7.1 has been running two websites without any problems (apart from an occasional mysql error) for, I think, about two years now. So there.

I just upgraded from 5.x to 6.2. I did the upgrade, and it mostly went OK, but now I get this...

Parse error: syntax error, unexpected '>' in /home/.extra/webbly/(mydomain)/includes/common.inc(1537) : eval()'d code on line 1

I checked that line, and there's no '>' there, which means the problem is somewhere else.

Thoughts?

Hello,

I've just upgraded from Drupal 5.7 to 6.2. It seems that all went well.
Now, I was upgrading the i18n module I was using in my 5.7 version. I install the module and run www.myexample.com/update.php. When the scripts starts to upgrade I got the following error:

Hello, a bad week.

I have been trying to upgrade to 6.2, but there has been some bug.. I have restored 5x, and the offline message has come on. However, under mysite.com/?=user I just get an ip address...as I am a php ignoramous, in the phpmysql interface, which table on the left do I click to change a 1 to 0 or vice versa--that is what I am assuming I need to do to . I have looked in system, but I can't find anything...is it elsewhere...I'm stumped about how to get back in now.

Larry