You can buy them together. Your barrier votes no on wearing them together.
AHAs (glycolic, lactic, mandelic) are water-soluble and work at the surface: texture, glow, the look of fine lines. BHA (salicylic acid) is oil-soluble, so it can travel into pores: congestion, blackheads, oily-skin maintenance. Different tools, genuinely different jobs.
Congestion and oil lean BHA. Dullness and texture lean AHA. Dry or sensitive skin leans lactic or mandelic (gentler AHAs), or a PHA, the gentlest option of all. If you honestly want both benefits, you still only need one per night.
If your skin ever becomes shiny-tight, stings under plain moisturizer, or flushes at nothing, you have found your over-exfoliation line. A week of cleanser, ceramide moisturizer, and sunscreen only, then reintroduce one acid at a lower frequency.
Combination formulas are dosed to be used as a single product, which is different from layering two full-strength products yourself. Even so, they count as your one exfoliating step that night.
Best not to. A retinoid plus any exfoliating acid in one routine is usually too much for the barrier. Alternate nights instead.
For most skin, two to three nights a week is the sweet spot. Daily exfoliation is rarely necessary and frequently regretted.
A free iPhone app that knows the right order for your routine and warns you when ingredients clash. No account, no data collection, nothing to buy.