Do I lose work in trial version after going to license?

I want to enter into the licence agreement for Scrivener but I’m worried I will lose all the work that I have created in the trial version. I don’t have anywhere to copy this considerable amount of text as Scrivener trial version is the only word program I have on my Mac.

Nope, you lose nothing.
Even the installed version of Scrivener you’re using now will be the same – the only difference will be that it would be registered and won’t “expire” after 30 days of use.

You can read more about Scrivener licensing in section 4.2 (beginning p.22) of the manual.