whenever I try to save it says:

Audacity needs the file; lame_enc.dll to create MP3s.

what does this mean!!!

No it doesn’t.
There is a subtle difference that must not be missed.

“Saving” in Audacity saves an “Audacity Project”. Saving an Audacity project does not require LAME. An Audacity project can only be opened by Audacity - it is not a normal audio file.

“Exporting in MP3 format” requires LAME.
“Exporting” allows us to create “normal” audio files that can be played in other applications.
Audacity supports exporting to a number of common audio file formats including WAV, FLAC, AIFF, and Ogg.
Audacity does not ship with an MP3 encoder, so on its own it cannot export an MP3 file. The reason for this is that MP3 encoding is restricted by patent issues (see: MP3 - Wikipedia ).
Audacity can export as MP3 if there is a suitable MP3 encoder installed. A program called “LAME” can provide MP3 encoding for Audacity.

There is some debate about whether using LAME (or any other free program) to encode MP3 files is legal in the US. Using LAME to encode MP3s is certainly legal in some European countries. We are not lawyers, so we cannot advise about the legality of using MP3 format.

If you choose to export as MP3, then you will need to install “LAME” (because Audacity does not include MP3 encoding). Details of how to do that are here: Audacity Manual

Personally I’d recommend not using MP3 unless you really have to.

If you’re trying to export MP3s for use in iTunes/iPod/iPad/iPhone - then you nay find it easier to export WAV files from Audacity and use ITunes to covert those to MP3.

That way you will also remain legal as Apple pays Frauenhofer for an MP3 license.

See this snippet that I wrote for the upcoming 2.0.6 Manual:

Format conversion in iTunes

Alternatively you can export to WAV or AIFF and convert to MP3, AAC or Apple Lossless in iTunes:
1.Click Edit > Preferences (or iTunes > Preferences on Mac)
2.Click on the leftmost “General” tab
3.Click the Import Settings… button
4.In the “Import Using” drop-down, choose “MP3 Encoder”, “AAC Encoder” or “Apple Lossless Encoder” as required
5.Click OK and OK
6. Select the file to be converted, then right-click or control-click over it and choose “Create MP3 Version”, “Create AAC Version” or “Create Apple Lossless Version” as appropriate.

After creating the MP3, AAC or Apple Lossless version you should delete the original WAV or AIFF files to save disk space, as iTunes does not do this for you automatically.