Minestrone is one of those hearty soups that you can just chop and leave chunky. I have over time just added what's in season or what I have in the fridge. My kids really love this dish but it could also be refined by chopping the veg smaller and served in a fancy bowl with croutons. As always, keep tasting and checking flavour/seasoning and also liquid levels. This isn't an exact science trust your palate.
Instead of a whole chicken you can also use legs and thighs to make about the same weight of a whole chicken.