I can’t get my 19 month old to pay attention or focus at all, signs of adhd/autism?

Re

I have a 19 month old boy. He’s very active ( will never sit down all day) very loving and affectionate and very determined with what he wants.

Today I googled ideas of what to do with him as he’s not been around children due to lockdown since March and I feel this may have had an impact on his development.

The activities are things like picking an odd coloured ball out of a bucket of white balls, playing treasure hunt and asking him to put things into basket, showing photos of animals or family and naming them, taping some lines on the floor into a path and getting him to follow the path. Etc.

What I’m worried about is I can never get his attention to show him something. If I ask him to come look at something or try show him something while sounding excited he just carries on doing what he’s doing. Asif I don’t exist. Even if I show him doing it myself he’ll just turn away and do something else and not engage in the play. I wouldn’t be able to get him to do any of the activities. we took him to the zoo and pointed out animals etc and he just doesn’t care and runs off. I’d love to try bake with him or paint but I know he wouldn’t stay to try it. We try pointing to areas of body and face and I can’t get his attention to show him what Im even saying. I call his name a lot and he won’t acknowledge me. But I know he can hear.

He doesn’t have a bad attention span though, if he’s playing legos he can sit happily for 20-30 minutes without me just building towers over and over and really concentrate on it.

I know kids don’t actually play WITH other children under their older but why does he not have interest in anything i try show him?