My son is 16 months. He says Nate and tried to say Elijah, and always says ma lol. But he doesn’t say much else. I always sing the abc’s to him and out of nowhere yesterday I said say A and he said it back so then I said B and he says that but won’t go to C lol. I’m not too worried. He will talk when he’s ready.

Teach him sign language!!!
My daughter wasn't speaking at 18 months, I taught her sign language and it really jump started her spoken language.
You can also contact Early Intervention ( you can refer yourself) and have them come out and evaluate your son. If he shows a 30% delay in any area he will automatically qualify for services and a speech therapist will come to your house. Early Intervention also works on a sliding scale based on income so it's not expensive.

He's still young, not quite a year and a half. Some babies have a really quick mental development but it's normal for your son at his age to still not speak much. All babies develope at their own pace and by the time he's 2 he'll probably be saying more words. My son didn't start talking much until he hit 2 years old and stopped using a pacifier, now he talks a lot but it's still like a gibberish sometimes but he's got a lot of words. I'd just keep showing your son things and letting him know what they are and talking to him and he'll pick it up eventually. If you're still concerned by 18+ months you can always talk to his pediatrician about early intervention.