First Mac and OSX 10.10

I just ordered my first ever Mac (the 11" MacBook Air) and it should be here some time next week. As this is my first Mac I'm going to have a significant learning curve ahead of me (this I know from my previous Mac experience, which has always left me feeling helpless as I simply don't know my way around).

The question I have for you guys is whether or not I should upgrade to the 10.10 beta right away. On the one hand, I don't want my new computer to be troubled by bugs or missing features, but on the other hand I don't want to spend a lot of time learning how to use my new machine only to have everything change a few months down the road.

So how do Apple's betas usually go? Should I expect 10.10 to be pretty stable, or should I hold off and wait for the final release? If I wait, how much relearning am I going to have to do when I finally do upgrade?