While there are no "trial campaigns", you can still create everything, find out where everything is etc, but just Pausing all campaigns until you are ready to go live. Only live ads will run, so in essence you do have a "trial campaign" in a Paused environment,
Re: Trial campaign
Welcome to the AdWords Community and to AdWords!
There is no option to conduct a trial campaign within AdWords, as the results are based on a live auction and the environment that you are targeting your ad in.
I would suggest, to create and AdWords Account, and create a campaign with a limited budget ($1-$3 per day) and set an end date for this campaign for a few days in the future (that way your "test" will not continue to run if you forget to log back in and turn off your campaign).
When you have a live campaign running, you will then be able to access the Keyword Planner, which will show you the results of your keywords (or potential keywords) in the current environment, but since its just going to show you the search results, you won't really know if your campaign will be successful with clicks and conversions.
Once you have run your first campaign for a few days, let us know how you did - and feel free to post any new questions to the Community!