Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
To start with, I need to know the version of mac osx you have on your machine, you can check as follows.Click the apple sign at the top left of your screen, then click about this mac. And then where it says version, send that to me as a reply.
Also, can you find me the A or M model number of your macbook, thank you.
This page should help you locate the model.. this is necessary before I can speak with any accuracy on this issue.
My apologies for the time it takes to reply to you. My reply has to be thought out and typed out to match your situation and be useful to you. And that takes time.
That does help.. Unfortunately, the highest version of Mac osx you can run is Snow leopard 10.6.8
You can purchase it here http://amzn.to/2blfuN4
And then you wo uld be able to run Safari version 5.1.1 .. But you wont be able to go higher then that, as simply put. The mac is too old to run Lion or Mountain lion, and to get current youd at least want to be running mountain lion, or preferably mavericks.
If you arent ready to pay the full price for a new macbook, this certified used macbook from amazon runs at 250$ http://amzn.to/2aPmoLZ and can run osx mavericks 10.9 which will let you run safari 7.
if you are trying to modernize to make use of the icloud features, that would be a low priced option to get you there.
If you have further questions, let me know.
I strive to provide great service, and greatly appreciate a 5 star rating clicked and submitted when you are satisfied.. I always answer follow up questions.Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.