Speakers of a given language can, by dint of speaking that language, pronounce the sounds of the language, so a Norwegian speaker can pronounce do, du, dy for you. If you ask a Finnish speaker to pronounce dy, you won't get the same thing. The association (IPA) has not sanctioned a specific set of recordings as the official standards for the letters of the IPA, and probably never will. For the moment, you can use demonstration charts constructed by recognised experts in the area. Peter Ladefoged's version is here. John Esling had an analogous chart, but it seems to be missing in action. (Aha: it crossed the ocean, here; you can also see various visualizations and two speakers).
There can't be a list of all IPA sound combinations ("ɓa, ɓɪ, ɓla, ɓlɪ, ŋɓa, ŋɓɪ...", since the set is infinite. I'm pretty sure that you are not looking for IPA combinations when you ask about "ay, ah, uh, at", instead you mean the IPA equivalents of some dictionary spelling system. Probably, "ay" represents the non-consonant of "may". There are a number of ways to represent that using IPA: [meɪ, me, me:, mɛɪ, mɛj, mej]. This is partially because there are competing phonemic analyses of the tense (long) vowels of English, and partly because the pronunciation differs – I go for [mɛɪ] as closest to my pronunciation, but people from The North (of England) are closer to [me:].
You could create a table of IPA-to-orthography correspondences using the CMU dictionary plus a near infinite supply of programming skill, since the dictionary lists very many putative words of English and their phonemic equivalents. (It includes numerous foreign words especially names, presumably because they appeared in some corpus; I don't know where they got their pronunciations from and I disagree much of the time). It uses a special coding where every phoneme is a string of blank-deletimited letters (" TH ") so you could convert that into IPA letters pretty easily. The hard part would be getting the orthographic correspondences, probably best attacked by anchoring consonant-to-consonant first.