What time of year will you be hunting and how long will your hunts be? If I was hunting 300 yards from my truck and only hunting a few hours in the morning and a few hours in the evening, I wouldn't bring much. I would bring my bow, 4-6 arrows, a knife, a flashlight and a drag rope. Anything else, I would just leave in the truck.
Toilet paper is handy to have. For nature's call and to mark a blood trail.
If I was in a tree stand, 300 yards from my truck, and shot a deer with my bow, here is what I would do. I would watch where it went. Make a good visual confirmation of where it went. I would wait until all was quiet and/or it was out of sight for a good 10 minutes. Then I would climb down from the tree and go to where the deer was standing. Mark that spot with some toilet paper and see if my arrow is there. I would then walk back to my truck. I would drop up everything I don't need anymore. I would grab a flashlight, drag rope and my compass and/or GPS, then return to the spot. At this point, we have given the deer some time to bed down and bleed out.
Of course, this timing depends on the hit. What I'm really saying is that you don't need a lot of stuff in the tree with you when you are that close to the truck. Less is more, in some instances. I would have some calls, depending on time of year, though. Especially if you are in mid-Oct through November.
I have taken the hunter safety course about 5 times. Once when I was 11 years old. A couple times with friends that were new to hunting, once with my wife and once with my son when he was getting his license. It was redundant for the last few times. But I enjoyed it. Especially because I was sharing it with new hunters.