I have responded to other threads with this short list of things that were instrumental to the success of my own two trips to Africa, tidbits I gleaned from my time spent on this site.
1. Practice from sticks or a tripod. I mean, diligently spend the time at your range at home before you go over.
2. Use this site to seek out a reputable outfit to hunt with. Frankly, with a little research you can unearth a treasure trove of top quality outfitters without ever needing to look anywhere else, and that's especially true for first time hunters to Africa.
3. Some of you are quite capable - good for you. But if you're going to Africa for the first time seriously consider a travel agent as recommended on this site and a meet and greet to help with rifles (if you take your own) on the other end. I like Travel Express and Rifle Permits Inc.
4. Establish good communications with your outfitter/PH before you ever get there. Be honest about your conditioning and any specific needs (health) you have.
5. Have a wish list (I did!) but be flexible once you are boots on the ground in Africa. My very first morning, while trying to get close to some wildebeests, we came across a fabulous bull eland. We had a brief discussion about it. My PH (who is also the owner) wasn't pushy but offered the chance to go after it. Eland was not on my list, but boy howdy, seeing him on that hillside... it was tempting.
6. The odds are you will go back again, but nothing in life is guaranteed. Take the time to smell the roses, and enjoy aaaalllll parts of the journey, not just the animals on the ground. Frankly, I can't imagine a mindset where the animals are all that matter. As a birder, seeing blue eared starlings in the morning sunlight was extraordinary. And I enjoyed my journeys through the various airports - it's so interesting to see differences in different places.
7. I read about this before going over: check the ego at home. As someone who has killed a crap-ton of moose, caribou, deer, and bears in my life, I feel like a pretty competent hunter. Some of those I killed on solo trips in wilderness areas. I am not a newbie. But I went into my first trip with a mindset of listening to my PH and doing what he said to do. No ego. He did things differently a few times than I would have, and it was fun to discuss those differences after the fact (which often followed a very successful stalk and kill). But hunting in Africa? I claimed no expertise, except knowledge of my firearms (lever actions!), left my ego in Alaska, did what my PH said, and had a magnificent time.
There is no one size fits all for everyone, but I think a good portion of what I experienced would work well for anyone going over for the first time. And for goodness sakes: ask questions on this forum. If you have something you wonder about, it's quite likely a whole lot of folks here have already done it.
One other thing, in spending time on this site: be true to who you are; not everyone here will have a completely similar perspective. For example: I do love to hunt with lever actions. They are not everyone's cup of tea, and I get that. But it never crossed my mind to use anything else on either of my two trips, despite a few suggestions by some that I would be better served with a bolt action. Be who you are.
Best of wishes to all who see this thread and are planning their own first trip.