Welcome
Those are the types of questions I suggest you need to focus on, straight up. The biggest weakness in use of FF programs is to spray earnings around and never ear enough points for anything worthwhile, nor gain any status.
My current goal is to grow points for now and then work out how to use them later.
Sorry, that's not going to work.
If you want to earn points for a 'free trip' (and you'll get to know that there aren't many that are actually 'free'), you sorta need to decide
now where you want to go. International: Americas? Europe? Asia? RtW? This will largely determine which FF scheme you join and more basically, which global airline alliance you focus on. OneWorld (Qantas etc), Star Alliance (Singapore Air etc) or Sky team (Delta, KLM etc, with affiliations with Virgin Australia). If your ambitions are only domestic, then of course its Virgin vs Qantas only.
If its OneWorld routes, then don't just think about Qantas Frequent Flyer. The earning on American AAdvantage is good, and the redemption rates are better than Qantas. Also, Qantas charges large 'fuel fees' for Award flights - such that for a Y redemption, the cost of cash 'fuel fees' almost as much as a discount Y fare!! American Airlines charges low fuel fees, as do a number of other airlines. This is what I mean about thinking ahead, and crediting to the scheme that will yield best results with respect to what you ant to do.
If you are thinking about Asia travel, you might think of joining Sing Air's or Thai's scheme (Star Alliance) but Aegean Airlines' scheme for instance allows you to qualify for higher status (better flying perks) more easily. Then you redeem points on Sing Air flights and enjoy the use of the Sing Air lounges
As you are flying to SFO on ANZ, that seems to be the best place to start - with a Star Alliance Scheme. You could join United Airlines' scheme, or Air NZ's, or even Aegean's but once you start, you should stick with it. others here can give better advice as to which Star Alliance Scheme might be best.
There ARE many ways to easily extra points (mainly for Qantas) by credit card use etc, even if you aren't 'trying'. Lots of info on various threads here.
So life gets complicated quickly, and I'm sorry if this all seems a bit bewildering; keep plugged in and you'll read and learn a lot. Even if you don't want to be that focussed on the issues as many of us here are, there are some simple ways to increase your earn and burn rates.
Good luck