As said before all the text is stored in the database and is edited via the languages section of your admin area.
In the latest version there is also "webmaster mode" if you activate this then you can pretty much point to something on a page and edit it directly.
This may be easier for you if your unsure of how to do things.
I suggest a good read through the forums as most things have been asked and answered before.
You dont need to know any java / programming etc to make basic changes and it may seem confusing to start with but you'll soon be up to speed. Everyone must start somewhere
