teenhunter,
You don't need to go out and buy new arrows just for your trip if you already have plenty of arrows that are in good shape and already tuned to your current set-up. Using arrows that you already know will fly true are fine as long as the fletchings are in good shape and there is no apparent damage to the shafts....If you buy new arrows and broadheads for the trip, I strongly suggest that you shoot them several times each before you take them to the field to hunt to ensure that they are flying in tune...
Inexperinced bow hunters often assume arrows right out of the box will fly exactly the same way as their other arrows...Don't learn that lesson the hard way... I've personally bought arrow shafts from the same manufacturer with the same spine and same advertised grains per inch that had completely different flight characteristics than the same exact shafts I had purchased a year prior. Some set-ups will show very little deviation even with sizably different total arrow weights, different fletchings, etc. My bow is very fast and not very forgiving. The smallest deviation with my set up makes a big difference in the point of impact for me. Don't assume your set up will be the same just because your arrows are the same... For Africa, I usually mark a half dozen arrows that I shoot the tightest group with and only use those on trophy animals. I take another dozen or so to shoot varmints, cull animals, etc...
Whatever arrow/broadhead combination you intend to hunt with is exactly what you should be practicing with now. Also, shoot your bow once you arrive in camp. My bow has been knocked out of tune 4 out of 4 trips to Africa... I don't know how they do it...?
Practice, study your shot placement, and you will have lots of success. Good Luck & have fun!