I need help writing a song, but I don't know how to write a song, or even make lyrics.

I doubt that anyone will write you a song, that's a big money business.
But you can start by simply writing down what you want your song to say.
It doesn't have to be in verse and chorus form.
Just jot it down and add to it as it comes to you.
Once you've done that you should be able to read it back and get a feel for where those thoughts go in a song.
Is this a song about someone special? If so, use that.
But remember anything you put online, even on here is public domain.
So be careful what you put on the web as you are doing this.

Ok, I am going to bite... LadySam has given you an excellent first start. What do you want to sing about? Music is basically a set of notes of various pitches set to a rhythmic pattern that is pleasing to listen to, which is the melody.

I have been playing guitar for forty-three years. I'm not a professional musician. I know basic music theory. I have improvised a lot of songs, but I've never felt compelled to write my improvisations down, and turn them into songs. I've written one song; a friend wrote the lyrics. I've finally decided, now that I am a better guitar player, to write another song, and in the process of learning to write another song, I will help you. But you have to respond to my questions and assignments in order for me to make the effort to help you. There are a lot of resources on the internet, now - I will refer to these resources to help you and me.

1. Do you play an instrument? Do you have access to a musical instrument? It is okay if you only sing.

2. Can you harmonize with the pitches made on an instrument, or with songs you hear on the radio? That is, can you match the pitch of a singer or a note struck on a piano or any musical instrument?

Your assignment - Decide on, and tell me, your topic. Songs are frequently written about love - lost love, jealous love, new love, unrequited love. Or about a stairway to heaven, or bricks in the wall, or a horse with no name. These phrases are usually allegories to some more meaningful aspect of life. Write two sentences of what you want to say in your song. I'm not going to give you lyrics - that is hard for me too.

I am asking you to write the call and response of the first verse of a song. The first two lines of a song often last eight measures. Don't worry about the rest of the song. The first sentence should be at least eight syllables to twelve or more syllables. The sentence should be a poetic as you can manage.

For example, the call "Yesterday, all my troubles seem so far away." is twelve syllables. Much more poetic than "My dog has fleas." The response is, "Now it looks as if they're here to stay." and then the classic hook, "Oh, I believe in yesterday." Notice how these phrases have an even number of syllables. I am guessing that may be because the song is written in common time - 4/4. (I'm guessing that a song phrase written for a polka, in 3/4 time, would be an odd number of syllables.)

Here are some websites to start with:
How to Write a Song (with 3 Sample Songs) - wikiHow (http://www.wikihow.com/Write-a-Song)
How To Write A Song For Beginners – A Step By Step Guide To Becoming A Songwriter (http://www.musicindustryhowto.com/how-to-write-a-song-for-beginners-a-step-by-step-guide-to-becoming-a-songwriter/)
How To Write A Song - Top Ten Tips - YouTube (http://www.youtube.com/watch?v=f3IFkhRTYsI)
Wikipedia definition of melody. (http://en.wikipedia.org/wiki/Melody)
YouTube: How to write a melody. (http://www.youtube.com/watch?v=rl-V2IsUprQ)
YouTube: How to write a poem. (http://www.youtube.com/watch?v=pYB3u9714IQ)

Respond, if you want me to help further...