In this kid's defence, I will say that, on occasion, I've mixed stims and psychs. I've been diagnosed with ADD. It was ethylphenidate and most likely a 4-sub. PERSONALLY, I found it a little easier to direct where my mind was going to chisel stone. For me, it aided in concentration, i.e., being able to stick with an idea, rather than it flies out of my mind faster than it entered.
Now, onto actual meat. No offence, but I had a growing suspicion halfway through the first page, screaming that you've never done psychs. Much like Xorkoth, my first experience was with 2.0 grams, or less, of dried mushrooms. It was the best psychedelic experience I've ever had. Understood 'god', laughed till I cried, cried because I'd never be that happy again. Total headsplode. Completely unplanned, but the groundwork of research had been occurring for years at that point. I was informed 'there's a fungus among us'. A quick hop onto erowid, years before I knew of bluelight, to refresh and , HA!, 'make sure I was ready'. As an aside, all my 'i guess I'll trip' trips are always way better than, 'I've been planning every minute detail and if anything goes awry, I'll die'
Maybe instead of being concerned with how many intoxicants you 'need' to break through, think about who will be around. Is there any one you know, and are comfortable around, who HAVE tripped that wouldn't mind being a sitter or tripping with you? Are you going to stay indoors or wander the streets? Have you chosen music? These are all things that will contribute to your trip, beneficial or detrimental.
Other than selecting substances, have you done any research, read big n dandys, read trip reports? These will familiarize you, but as stated, 'it's only the tip of the iceberg'. Be safe and pop that psychedelic cherry in a way that lets you keep exploring.