Vang, topping lift, traveler.
Well, you want the topping lift slack, so it doesn't fight your mainsheet when trimming close-hauled. Otherwise, forget the topping lift (except maybe in zero air if the mainsail leech is too tight).
Vang. Use it downwind, keep fairly tight to keep the boom down and avoid too much twist in the sail. Upwind, if you have one, you use the....
Traveler. If windy, ease it to lee a little, or a lot. Once the mainsheet is close-hauled, it becomes your up/down leech loosener/tightener, which helps you flatten or make fuller, the Main. The traveler then is your in/out control (like a mainsheet, but with a narrower range. Use leech telltales to see how the leech tension and twist are, you want them to flow aft.
Way more to say about all the above, but many web sites say it better, and longer.
You didn't mention halyard tension (or cunningham, or downhaul if a sliding gooseneck), outhaul, or backstay. Generally tightening them flattens the sail (for windy conditions, or for smoother water), loosening makes it baggier for lighter air or choppy sea (like a lower gear on a car or bike).
then there's the jib. same deal re halyard tension, and fore/aft side/side angle for the jibsheet leads.
Much depends on the boat, the sails, and the conditions. Racing's boatspeed first, then clear air above all, tack on headers, stay on lifts, don't be over at the start, don't pinch too much, don't foot too much, mark you ballot carefully, and keep the ball low...;-)
Enjoy racing. Best sailing school there is. Eventually someone else's ass will be getting kicked, you're up to mid-fleet, and liking it a lot more.
Okay, this will get it started? others chime in with better pointers than me.