Only if you're in multiple channels and only want it to work in certain specific channels.
If so, go through the code and find each line that starts with the word ON
Near the end of, most of, those lines, you will see the # character.
Replace the # character at that location with the name of the channel you want it to work on. If more than one channel, separate the channel names with a comma.

This code sends a message stating what channels the person that just joined is also in at the time of the joining, and it is sent via /notice to all of the ops and half-ops in the channel.

You're going to have to clarify what you mean/want by in reference to "A menu or a place in the code to enter a channel and msg or anything?"