For the sketch up free trial after your trial is over can you still access your document that you created from sketchup
That sort of depends on what you are trialing and what you mean by access.
Desktop versions after 2017 give you a 30 day trial of the pro software, then after that unless you pay for a license the software will stop working. You can still access your models in the Free Web Version.
2017 and earlier give you a 30 day trial then revert to the free make version without access to the pro parts of the software.