save the money and bet on charity, keep doing that until you have nothing to bet on, or run out of money. keep it on a running cycle so that you always have money coming to you. that's what I'm trying to do.
Do what Jacadu said, but as what you should do first just matters how you are in challenges. LG does very little so it's you don't have to get it asap. If you are better than like 60%-70% of people at them you might be able to get a merge or two on the right tribe. Join with friends if you can. If you do choose to join, look try and find a time where there a lot of bad tribe and few to none good ones.