Getting an item from an array in twig

Need Help
#1

I have a tailor collection, but when I try to access an item inside the array by index, I get nothing

{{ categories[0] }}

when I encode the collection and print it out, it does indeed look like an array
I am stumped

is there a way to check type in twig?

#2

try installing this plugin and see collection structure

{{ d(categories) }}