How do you make money on secondlife? And how does a newbie start having fun?

Answer 1

You make money by
1) making stuff to sell, either by Building, Animating or Scripting
2) get a job or provide services
3) spend silly hours and make lag by "camping" for a few miserable L$
4) just bite the bullet and periodically buy Lindens; it's entertainment. VERY very few people make any real money in SL.

You start having fun by
1) exploring
2) taking classes or attended events or discussions
3) join groups
4) work on your avatar and building/animating/scripting.
5) figuring out what interests YOU :)