Good luck!!
I’m a bit of an evangelist on the topic of getting it taken care of. My first scope was a “while we’re at it” when a gastro wanted to do an upper GI. A friend’s husband died, after battling colorectal cancer for many years (to be fair, he developed it when younger than the recommended screening age). A neighbor has been ill for several years. I do not ask for details of his prognosis. And a friend of mine went in for her colonoscopy for what she thought were likely hemorrhoids… stage 3. She’s going through chemo right now. A colleague’s husband was (as I gather, I did NOT ask) avoiding screening… and had a somewhat urgent scope late in November a couple years back. They got the news that it was cancer- merry fucking Thanksgiving 
He lasted 6 months. And of course our own Maggie the Ocelot (again, younger than the standard screening age).
Here’s a writeup I did a few years back, after my 4th or 5th one.
For tomorrow (today, by now, LOL): if there’s a pho restaurant near you , pick up a couple of quarts of their broth to bring home. Tastier than store-bought broth, and especially if it’s cold where you are, the warmth will be nice. Likely too late to get and install a bidet toilet seat - when we tried one a couple years back, I told my husband, “we WILL have the fancy heated-water one in the master bathroom before my next scope”. We did - and it made a big difference. Depending (hah) on how your gut tends to behave in general, you may find a package of disposable underwear to be helpful. I bought some, the last time around, due to some unrelated gut issues, and was glad of it. If your bathroom tends to be on the chillier side, as ours is, get and set up a small space heater - you’re gonna be in there a lot.
And as far as that after-session meal: dunno if that’s supposed to be at a restaurant, or at home. I learned the hard way that a restaurant meal is risky, as it tends to wake up the gut… with unpleasant results. I don’t think most people have quite as much trouble.
But in any case, good for you for getting it out of the way! (or, as my primary care doc said, “it’s behind you now”, to which I quipped “so to speak…”).
And for some funny reading: Dave Barry’s column is well known. A lesser-known, but frankly funnier, story is here. (the tl/dr version: double check your appointment date and time very, very carefully).
My oft-repeated offer: to anyone within a hundred miles of Washington, DC: if you need a responsible (quit laughing!!) adult for yours, and cannot find anyone, I will volunteer to do it. Just give me a week or two notice.