Normal behaviour or autism signs?

[Newmum26]

My DS is 18 months and a bright little boy who learns quickly you only have to show him something once and he remembers how to do it.
His talking is amazing, he is so clear with his words and talks a lot copying every word you say he gives it a go.
He's affectionate and cuddly and shows no 'red flags' of autism but I'm worried about one or two things that I'm not sure if they are normal developmental behaviour or not.
He has 'obsessions' he loves Apples 🤣 In books he will point them out and say 'apple' and in one of his lift the flap books he remembers what flap the apple is under!
He had play food and likes to carrying his apple around but also plays nicely with l his other toys and play food.
If we pass a tree with apples on he will point and say 'Apples!'
We've always thought it was cute and funny but I'm worried it's an ASD sign.
He also had his little routine, for example if we go to his grandmas he knows his toys and tractors are in the bedroom and will go straight it and head for the bedroom saying Tractors!
Can toddlers have obsessions or things hey love and it be normal?
Thanks so much for reading! :)

I would say that's totally normal for a toddler.
You probably wouldn't think it was strange if he had a favourite toy or bear he carried round and then pointed it out everywhere he went. Example if he loved woody from toy story and carried him around and then pointed at every tv, book, dvd cover etc. To grown ups apples are a strange thing to like but toddlers don't have that thinking.
Going to your mums Is normal too, he will soon change his routine to the go straight to the biscuit cupboard  that's where my 5 year old heads every time! She is always starving when we get to grandmas

We've always thought it was cute and funny but I'm worried it's an ASD sign.

When DD was 18 months, she had a very similar obsession with flowers. Pointing to them in the street and in books, pulling me in their direction when we went for walks. Now she is 22 months and while she still likes flowers, she is no longer looking for them everywhere. She has moved to chasing every single dog she sees. I feel it is a normal part of toddler development - to get interested in certain things and then move on to something else.