Our team is relatively quite new, but have no regrets for jumping in a few years ago.
My 2 cents..., from our world.
(1) best you can afford packer trimmed before hand in case it's gashed, (2) butts trimmed ahead, (4) slabs, at least (24) chix pcs (absolutely pretrimmed), stupid amount of pre ordered parsley.
No matter how stupid the step may seem write it down with timing in your practice cooks.
Willingness to wing it when something goes off schedule, and adjust on fly...trust your gut.
Practice cook again...as you use it set it on one table, when done there are your essentials.
Also a "kit" of on the fly adjustment ingredients.
One tote or drawer dedicated to each catagory.
4 meats only, ancillary cats are detrimental distraction, we have been lucky with a salsa thing, but bad risk reward investment commonly, at least in our semi newbie opinion.
water
Ibuprofen
energy drinks, or awesome coffee.
Redundant backup stuff...one extra of every hardware category, ex. Cord, light, power supplies etc.
This is what I have off the top of my head, and I am sure I missed some.
Perspective...
Willingness to soak in advice, disappointment, success, and all in all an awesome time in a great community of folks!!
Good luck & above all enjoy yourself!!