Get him checked out, or get information from an experienced medical specialist, and observe for a while.
Stay away from amateurs (including me BTW), and be very cautious of any web site that is making money from "young adult" and adult ASDs.
Also be aware that there are people who falsely claim to be ASD for self-serving reasons. it's not likely you'll "bump into" them accidently, but be careful.
Worth checking early in whatever documentation you get from a serious source:
* Timing of development of language skills
* Timing of development of "non-verbal" communication skills.
e.g. (NT toddlers watch the faces of adults they know often and very carefully, and similarly pay attention to and react to tone of voice.
FYI I spent a while (6 weeks or so) around a 2-year old a little while ago, and was lucky enough to watch him go from knowing (and speaking) a few words to framing simple sentences, and simultaneously converting passive to active vocabulary (I think - can't prove that, but its a good fit to my observations).
I'm 90+ % confident that's NT normal behavior, but don't know about the age range such things happen (my kids are adults - I've forgotten all the details).
He threw a few tantrums while I was there, and engaged in what we'd call anti-social behavior in an adult. As all toddlers do.
They don't really start learning emotional regulation until 4 or so (IIRC - check some literature), and they're not done until they're tweens (if they not harmed by a poor upbringing, in which case poor impulse control and "learned narcissism" are possible).
While they can't regulate their emotions, they (naturally) have difficulties regulating their behavior, and they're liable to get temporary "brain locks". A few brief periods of chaos are to be expected.
OFC I can't say if any of what I said is useful for you. I doubt absence of those things is enough to draw any conclusions. But their presence (even the tantrums) is a "non-determining" indication of normal behavior.