Think my son might have a diagnosis

My son is three years old. Ever since he was about two he started falling behind on his speech and I started thinking he might be a bit behind/different mentally as well. I know you shouldn't compare children, but it's hard not to when you realise your own child is really far away from where everyone else are. It's my first child, so it's hard for me to know where he should be and what is normal and not. I have worked a bit with children with autism, adhd, etc and haven't really met a lot of children without diagnoses and I guess that makes it even harder. I see a lot of similarities, but also a few differences.

Here's a few things:

He doesn't really respond to his name, often it seems like he doesn't listen at all (his hearing is fine, we have checked it recently)

He doesn't really make eye contact

He has a hard time concentrating, unless it's something he really cares for, like vehicles

He doesn't respond to other people's emotions and doesn't really seem to understand them

He doesn't point at things and doesn't really look when you point at things

He doesn't play pretend games, only very simple and very repetitive plays, like playing with a train that crashes into a stone over and over, and doesn't really play with other children

He is behind on his speech and only really uses a few words and phrases

He has no concept of danger or consequences

He doesn't care for praise or for punishments, although I don't really use punishment, but I will sometimes take away things when he doesn't handle them in a good or safe way and he never cares

He has trouble eating food and only wants to drink

He doesn't seem to notice his needs, he never asks to go to the bathroom, expresses that he's hungry, thirsty or tired

He always plays with the same toys and likes to line them up

He is very active

But on the other hand he doesn't have any problems with different routines and routine changes, he is very cuddly and wants to be held by people he doesn't even know well, he rarely have meltdowns and when he does they pass quickly, he has no issues with sleeping and sleeps a lot, he likes being around people, and has really good motor skills.

I will seek help, but I'm curious to know if you have a child with a diagnosis, do you recognise these things and what was the signs that your child had a diagnosis and how old were they when you started suspecting things were different or when did they get a diagnosis?