If you on board a little early and want lunch go to the Lido deck and look around at all the options. Our first cruise, we jumped into the first line and fixed our plates, then realized that there were a lot of other stations that we could choose from (salad bar, deli, pizza, sometimes a fish and chips, grill etc.). After lunch you might also want to take a tour of the ship before it gets too crowded. This will help you become famililar with the different areas and help you find your way around.
If you are not handed a "deck plan" and "Caper" when you board, you should pick them up at the tour desk counter. They will help you get around even before your cabin is open. We like to carry a highlighter and highlight the events that we want to attend the next day, then take the little tear off column from the Caper and stick it in our pocket for easy reference. The less you have to tote around with you the better.
Have a great time - take things in stride - and remember everything will not be perfect but it will be as fun as you make it. There is nothing like the "First Time" in Love and Cruising.
Been there - done that:
2005 Holiday, Sensation, Conquest,
2006 Conquest, Celebration, Holiday,
2007 Freedom Grand Med, Holiday
2008 Fantasy & Sensation,
2009 Fantasy, Holiday & Dream Grand Med
2010 Fantasy and B2B Elation
2011 Monarch of the Seas
2012 Booked - Breeze from Barcelona 12 days