Hello MrT. I'll break it down by common acid types used in skin care, what they're used for and what products they're usually found in:
Hylauronic: helps skin retain water, keeping it hydrated and plumped up. Good for fine line as a result, but the result is temporary, as it plumps wrinkles rather than getting rid of them. It's very "in" at the moment, so can be found in pretty much every stage of a skincare routine, but it would work best in a serum that goes on before moisturiser. Something like Hylamide has peptides and other things beneficial to the skin also.
Glycolic: exfoliates the surface of the skin, removing dead skin cells and brightening. Improves skin texture and can help with fine lines. Most common in acid toners, which are to be used after cleansing, before serum and/or moisturiser, although you do also find serums called things like "overnight treatment" will contain it, as will some moisturisers. Depending on your budget and tolerance for strength of product some good ones to look at are Bravura, Pixiglow (I personally don't like this, but that's because it's not strong enough for me. Lots of people love it though, and it is very gentle), Nip+Fab Glycolic Fix (the extreme pads are good, have more than one acid, and aren't really "Extreme" at all).
Salicylic: Application and stage used at, etc., same as above, really, but this acid will go beneath and clean the pores, rather than surface exfoliate. Good for oily/combination or blemish prone skin, particularly blackheads. Clinique Mild Clarifying Lotion (only the "Mild" one) is a good salicylic only one. Nip+Fab Dragons Blood pads are nice too, very, very gentle.