Very few people are tone deaf. Simple test: have someone play a note on a piano or guitar while you are facing away from them. Then have them play a second note. Have them vary between playing the second note the same as the first and different but close - a half step or whole step away. Most likely you will be able to tell if the second note is the same or different every time. If so you aren't tone deaf. You might have to work hard to be able to hear smaller variations in pitch and you definitely will have to work hard to hear your own voice accurately, but being able to sing is a pretty basic human talent. The only problem is that it takes practice and for some reason people are more embarrassed by their inability to sing than their inability to dance or type or play an instrument.

You'll be able to do it and you can get better pretty quickly if you put your effort in the right direction. Get a good teacher and have fun.

FWIW-

Families aren't tone deaf. In fact, very few people are. if you can distinguish between high and low pitches (not volume) and your voice can approximate the high/low then you have the ability. How far you go is based on talent and hard work.
A friend of mine was told he would never sing so he took up the guitar and got pretty good at it. He was accompanying a vocalist's audition when my high school choir director encouraged him to audition.
He started singing in his senior year of high school, went on to be a vocal music major, got his master's in operatic performance and makes his living by touring as a soloist and feature operatic lead throughout the world.
He was always a year or two ahead of me and we went in different routes after college (I was the jazzer and eventually the teacher) but we've both made a living out of music.

Phil

There are 3 types of singing.

1- The proper way and that is to breath with your diaphragm crating an opening so that your vocal cords vibrate. When they rub you get polyps among other problems. This is the way opera singer sing and accomplished pop artists who really have a voice as with Whitney Houston and Patti Labelle. They teach that in the Church too.

2- Chest, for the life of me some people sing that way and sound OK, I don't know how they do it. It's common in rock music. Roger Daltrey was the best at it.

3- Throat, this is the worst way and can cause you to loose your voice. It the most common for poor singing and the worst and improper technique.

Although some throatiness adds to the tone and is important in certain types of music like gospel, blues country and so on. Too much and goodbye voice, some times for good.

So if you want to sing learn the proper way to breath first by going to a teacher not a coach. You use coaching once you have learned the proper way to sing.

You don't have to have it down like an opera singer to sound good. Some people have a natural voice and use all 3 of the techniques to get the song across.

The most important thing is called pitch. If your sing flat it's usually because your mouth is in the wrong position and/or you're not sure of the note.

So learn what each note sounds like and try to reproduce it consistently, that with learning proper breathing will at least teach you to maybe carry a tune. Maybe not, some people just can't sing. It has a lot to do with how you are built in terms of Length and width of you vocal cords, voice box, length of neck, size of mouth, lips...many, many factors.

If you have a deep voice it's harder to sing because most music is for people with higher voices.

a couple really basic things to try......most people have the old do,re,me,fa,sol,la,te,do......embedded in their brain, if you do sing it, sing it in the car on the way to work, if it's not in your brain get a guitar or piano, and play a scale in a comfortable register and hum/sing along with it, say do,re,me,etc, It shouldn't take to long to get it in your head.....and be able to sing it without accompanyment.
Also try/practice singing some of those really simple songs that are probably embedded in your head, like Happy Birthday, you probably won't even need any instrumental accompanyment to sing stuff like that...

Evidently there is alot more to singing but that's some pretty basic stuff....
Also pay as much attention to your timing and rhythm as your pitch, try tapping a finger or foot, or moving you body in time while you sing, it might seem hard at first but it will really help in the end. Music, songs and melodies are in your head that you probably don't even realize and rhythm will bring them out. Try not thinking about them, just get into the feeling of the rhythm and you might find that they start coming out and you are singing them without consciously thinking about them, once they start coming out, after which you can refine them, once you start getting them to come out.
Oh and try singing along with music (vocalist), just make sure it is something not to difficult that suits your voice. Imitation is also a great teacher when you are starting out.
And as you move along, always be looking for that next little thing that will make you sound better.......
And don't get hung up on singing properly, that is sing with the head voice and all that....yup it's important and you should learn it at some point....but there is so much more to good singing....phrasing, rhytym, diction, voice character, and list goes on, alot of people get hung up with thinking they need to be belting out high notes, and they end up sounding like a fog horn. When you hear a good sing on a recording pay attention to all the little sutleties in their voice.
whew ...enough said for now. good luck......and don't get discouraged