If you want to put the Mp3 audio lessons and the PDF text files on your iPhone/iPad, you have 2 choices:
(Computer to iPhone/iPad) This is the easiest way. Download these files to your computer. Go to iTunes and add the PDF files to your iTunes books section. Add the Mp3 audio files to your iTunes music. Sync your iPhone/iPad.
(iPhone/iPad App) There are also some free apps on the app store for downloading files to your iPhone/iPad. These apps are always changing so I cannot guarantee that they will work. Here's one you could try: "Documents by Readdle."
You can use "Documents by Readdle" to visit our website, download the files, read the text files and listen to the audio files. "Documents by Readdle" is one of many apps that do this.