Without a screen grab or something, it's impossible to accurately diagnose what's wrong.
But typically, a linked piece of text can be achieved either by having the text Precomped into a separate composition, or by applying an expression to some or all of the text layers that are required to mimic the "master" text layer.
One cause could be that the top line of text is intended to be an unchanging headline, and that the the corresponding layers' Source Text property in all the comps is linked to the first by an expression. Have you checked?
You are changing the text in a pre-comp that is being used in all other comps. Duplicate the pre-comp, replace it in your main comps.
Thanks for the answers, im new to After effects so if you can assist further with how to do that it would be very kind.
im new to After effects so if you can assist further with how to do that it would be very kind.
Sorry, but probably not. The reason: AE comes with its own arcane terminology which people would use, but which you wouldn't understand. There's a language barrier.
If you don't know how to cook, it would be like a step in a reciple for lasagna: you read, "make a chiffonade of six basil leaves". You might respond, "What the heck is is chiffonade?" and someone might explain, "Roll the leaves together on the long axis and give them a fine slice." Then you ask, "Well, what's a fine slice? An inch? an eighth inch?" And round and round it goes, with you asking questions and people explaining the cooking basics to you.
If you purchased a template in the hopes of AE success, you sadly made an unwise purchase. You need to learn the basics to even modify templates, and here's where you learn the basics.
I agree with Mylenium about the likely cause, and with Dave about the need to learn the basics so that answers like Mylenium's make sense to you.
What Mylenium is saying is that you have a single composition that is being used in many places, so changing that composition will cause changes in many places.
You need to duplicate the composition _in the Project panel_ (i.e., don't just duplicate the layer in the Timeline panel, which is probably what you did to get into this situation).