The best way to avoid a bad trip I've found, is to have the proper location. My suggestion is out in the woods (with at least one friend for safety and fun purposes), though make sure it's the kind of forest that's soothing rather than creepy. I suggest finding a clearing, somewhere away from trails so there's no worry of bumping into strangers if you're not clear-headed. Make sure it's a pleasant, sunny day, gloomy weather can give forests a creepy vibe.
Secondly, have some lighthearted movies on a phone, for when you're coming up. They will distract you and prevent you from worrying. Your thoughts as you're coming up will affect the balance of the trip, so you want to be as relaxed as possible. I suggest watching some quirky, fun, kids movies (i.e Flubber, Toy Story, etc); they're good for soothing you when you're tense. Take a break about 40 minutes after taking the tab though, as it's easy to get so focused on a movie that you don't really notice the trip (at least at low doses).
As for the medications you're taking, your antidepressants will directly interact with the LSD, at least from a biological perspective. How it will affect the experience depends on a bunch of variables, primarily dosage. Most people find that SSRIs weaken 5HT-psychs (LSD, Shrooms, 2Cs, MDA, etc) effects. I suspect this is primarily due to the downregulation of 5HT2A receptors, the primary type of receptor affected by serotergic psychadelics, and Wikipedia seems to corroborate this possibility:
What this means, is that not taking the drug the day you trip probably won't make a huge difference, as the reductive effect is actually the result of long-term brain adaptations, not the drug's acute chemical effect.
I would not take the SSRI with acid due to the risk of serotonin syndrome. The risk with acid is much less than it is when combining SSRIs with MDMA (which can be very deadly), but it's still there. The Wellbutrin (Buproprion) is safe with acid (though it could interact and affect the trip), as it works primarily on dopamine, with no binding to serotonin receptors or transporters.
The Abilify is not unsafe with acid, though it will likely significantly reduce the effects of it, as it is an antagonist/inverse agonist of all of the serotonin receptors. Since acid works primarily by stimulating those receptors, you're essentially canceling it out (depending on your dose). I suggest not taking it if you want to have any kind of trip. It's also odd that you've been prescribed it, as it works through the opposite mechanism of your Prozac, reducing serotonin activity (while Prozac increases it). Together, they pretty much negate themselves. Both drugs have other mechanisms as well, but their two primary mechanisms of action contradict each other.
Xanax would be great to take right off the bat if you have anxious-tendencies (i.e if you're obsessively worrying about having a bad trip). It'll mellow you out while still allowing you to enjoy the acid. However, if you're not to anxious about your first time with acid, I'd suggest seeing how you do without it, and saving it in case you start going down the bad trip route. It's nice to have a clear head, and you'll remember the trip better if you're not under it's influence (Benzo's have mild amnesiac effects).
