The method is the same as 10 years ago: Export as mp3. Menu “File → Export Audio” and select mp3 as the export format. The newer versions of Audacity don’t need the installation of third-party software for exporting to .mp3.
If you want to split a recording into pieces (individual songs etc.) you need to set markers where to split the recording. Have a look at the Audacity manual.
Please also note: Adding your question to a 10-year-old topic - which is also marked as “solved” - does not help to draw the attention of others to your question…
Edit: a moderator seems to have separated your question from the original thread now.