For the most part, music audio in the game should be 44.1kHz, 2-channel, 16-bit, which would be "CD Quality". I do not remember the kbps off the top of my head for mp3 files, but probably 192. Find an mp3 in the stock game, and match its settings. The wav files for sounds vary, depending upon their use, but again, have to match the Stock game's examples whether mono or stereo, 8-bit or 16-bit, 22.05 or 44.1kHz, etc., and might also be length-restricted. A 48kHz "video" audio generally will not play in the game, other than the Intro movie when the game starts. If you don't have an app that can edit audio, you can accomplish edits with
Audacity Editor, but it can be a slightly complicated process in that app, and might take a bit of experimentation for the "export" settings.