Help my site links not working after server upgrade. v1.2.7

My web host has upgraded their system and now my catagory links no longer work, but the links on the right side of the page still work (this seems kind of weird to me that some would work and others not) but I need to get them all working so could someone please visit my site and give me advice on what to do.
I think that I need to upgrade- I am currently 1.2.7 however I was reading somewhere on this forum that I need to do some special procedures or something so that I will not lose my upgrades? can anyone tell me if I even have any upgrades on my site? The guy that built my site is gone so I am on my own with these problems. Any help would be appreciated.

P.S. I think that the guy that built my site told me that the brushed stainless steel background was an upgrade. Is this correct?

My site is https://www.bottlingtechnologies.com

Top get this back online - see if your host can set your account to use mysql 4.x

This would be a temp fix while you upgrade

1.2.7 was used by Noah when he was buying components for the Ark. You really must upgrade - both for software and system compliance and for security reasons.

Kobra, I talked with my host LunarPages and they are no help at all - They said that they no longer have any Mysql 4x systems and that I should just change some of my html and the problem would be fixed. Is this correct???
OR
Do I need to upgrade to resolve this issue and if so Is it going to be very complicated and time consuming to do so. I am planning on purchasing the Zen-Cart book but by the time I read and get through all of that I dont know how much time will have gone by (I was just starting to get some decent page rankings on some of the search engines and dont want to lose the progress that I have already made)
I guess to get to the point is this something that I can get through with just the information on the forum and my very limited knowledge

Do I need to upgrade to resolve this issue and if so Is it going to be very complicated and time consuming to do so.
I do not think your site will be that difficult to upgrade but do not know all of the mods you might have applied...

Enevitably, you need to upgrade but you site should not have to be down during that time.

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