Qin, the teenage division is open, so you'll be one of the heaviest there.
USUALLY they are divided into LW/HW teen which is under/over 200. Here we have only open this time.
Your lifts are very good in an absolute sense and relatively for your size they are quite respectable as well (I assume your numbers are based on RAW powerlifting - or wraps+belt only). 255 was my first OH press in my first strongman in January 2008. That was a middle-of-the-pack LW number so that should give you a sense of how substantial that is for a teen.
If you are up for it, and can sustain the travel depending on where you live, on Wednesday or Thursday you can stop by and we can show you the implements.
If not, here are my thoughts.
Many things in strongman for the first time are hit-or-miss for the competitors. Yoke and Farmer's especially - if you are built with a wide, thick-hipped body, yoke carrying will be more natural. If not, slap on two (or three if you can fit them and if it's allowed) lifting belts and do the best you can. I am assuming, however, that the reason you're in a 265 class is NOT bacause you are 7 feet tall.
Farmer's holds depend on grip strength (obviously) so if you have the large hands and forearms for it there is not much to learn. If you have small hands and wrists it will take a lot of grit to improve over time and there is also nothing to teach at this point.
Viking press is a mechanical press - since it is attached to a pivot, focus on leaning into it and throwing the weight FORWARD, unlike a barbell where you throw it behind you to maximize power. Put your head through the press as always but think of leaning your body forward into the weight while you do, rather than on your heels as with a barbell.
Keg carry is subject to certain preferences - I can show you how I do it, which is the most efficient way over a long carry since I am a lighter, weaker competitor where athleticism is the key.
Tires all have their own personalities - some have to be deadlifted and curled, others can be shouldered and angle-squatted. A few practice flips wouldn't hurt ahead of time. After that, it's a matter of practice and conditioning. I'd say fast time in tire flipping is arguably the most affected by perfecting technique of all events in strength athletics.
On game day I'll show you a few things I do for the implements since I'll most likely be staffing not competing (I have some nagging injuries and with ILSM in the crosshairs I ought to forgo this one).
I doubt you'll get 'destroyed' - I've seen the performance of some of the teens. They're strong, but most of them save for Brad Baldwin are novices too and he weighs 170 at like 6'3" tall. In any case, however you do, everyone has a first meet - this one is all about getting teens and novices into it - with eight of you, you guys will be the'main event'.
I look forward to seeing you there.
DM