yeah - it doesn't matter if you are VIP or not it will still detect O - it just won't show all the other stuff on your chart (like symptoms

) or give you the pregnancy monitor and stuff. But if you only just signed up for FF they normally give you a complimentary VIP membership for the first 3 months anyway - so you can see what you're missing.
And I would say start temping now - it will get you into a routine and if you forget to temp it won't matter so much. And as Chelle said it will allow you to start seeing patterns and allow you to compare.