How can i come out ?

(His first name isn't Ulysses, I hope.  Because HE's got a girlfriend.)

Seriously, young man...just take your time and enjoy your friendship for now.  You don't need to inform Mom right away.  It could be that this relationship won't last all that long.  Just give it a chance and see what develops between the two of you.

If it does turn out to be a nice, steady relationship, frankly your mom will probably know about it without you saying a word.  If she wants to know details, she'll ask you.  Why don't you just wait for her to ask?  At that point you can either spill the beans, or you can claim to just be good friends who like to hang out together...it's up to you.

There's nothing to be gained by being anxious to share.

you just tell her.  

the good news you cant knock up your partner,,,,,,the bad news no grandkids

If you think she might not accept it, maybe you should think about keeping quiet till you're old enough to take care of yourself. I've read posts on here from so many people whose families threw them out when they told them. Good luck.

Hold up on the urge to tell the world for now. Regardless of sexual preference, ppl in new relationships often want everyone to know. At your age, it’s prob best to see how this goes for a few months, because younger ppl are often fickle. It could be age or stage, and your mother may conclude this too if you present too soon. 

Wait until you are able to move out on your own. You may be kicked out of the house. Being gay in Alabama is not very popular as you should know.

Depends, how easy you think they will take it. It's growing more common now not to come out and to just introduce your partner to your family and take it from there. If you feel they need to be eased in to it then I would just wait until they are in a good mood and then just tell them. Typically a lot of people just say "Mum, dad, there is something I have to tell you.... this helps to lead up to it. Either way whether or not the relationship lasts it's still wise to come out so you can get the aqwardness of your family out the way. They may have negative ideas about being gay which will need to be corrected.

Unless you know for a FACT that she will be supportive, don't tell her. Keep your bf a secret until you're both ready to leave home and make your own lives without your parent's help.If you DO know that she'll be supportive, just sit her down and tell her you have news that makes you very happy, and then tell her what it is.