I agree with your friend, it's never too early to start a good investment !
Then you'll have to go for an Etoupe or Black 35 cm Birkin with palladium if you intend to get out in a short term, if you are a long term girl, go for a crocodile Kelly in any color, or for any bag ( Birkin or Kelly) in a bright red, any hardware !!!
More seriously, make sure you buy the bag you really like and that fits your life style..that's the best way to start off your collection
As other members say, take your time .... May I suggest you to watch the action thread here....it is a very instructive way to build your own taste. There are all kinds of ladies there posting pictures of their outfits and bags, in the most genuine way....