My first time would have been either 16 or 17, in a voc prep college. Neither the best or the worst quality phet, not paste but crystals.
Most messed up place ever taking any....it was meth, just after an operation while I was waiting on the ward, because the fucking bellends were refusing me my prescription meds, including pain and antiseizure meds and nitrazepam. For no comprehensible reason at all, they refused to give me my meds while I was there, despite being shown my old repeats etc so they knew what I should be on, then on discharge, gave me masses of them, and stuff I wasn't even on, such as 100mg morphine caps and along with my usual oxy IR capsules, they gave me a couple of full bottles of liquid oxy, and two hospital pharmacy stock-bottles of chlormethiazole, left with hundreds of those, no doubt to shut me up and prevent me from dropping them in it with a formal complaint or lawsuit. Got my regular script the next day too.
But during the wait, I'd dropped 2 or 3 tabs of 1p-LSD, 40mg of 2C-B-FLY, some DIY meth (D-meth, via Birch reduction of PSE), and some of the 5-fluoropentyl homolog of this
https://en.wikipedia.org/wiki/CUMYL-PINACA , an extraordinarily potent, although short-acting synthetic cannabinoid, as well as some chlormethiazole, moggies, morphine and oxy I'd sneaked in)