Hi Keen wah...
First of all welcome to pet pitcher forum....
The best way to start a collection is to try on established plants which you could get from nursery or some reliable contact...
Nepenthes seeds is not a good option for starter because after germination nepenthes will take at lease 2-3 years before they mature... "for some people this 2-3 years period will be like forever...."
Anyway good luck on your carnivorous plant hunt
as for cultivating of carnivorous plant if you have any question feel free to post in our discussion board i'm sure you will get a hand full of good advice form our fellow forum members^^
Regards
Jonathan