What is correct grammar here: "I want some too" or "I want some to"?

“Too”!

I want some, too. (notice the comma)

Too means also and why the comma?

My Norwegianess should only be as good as your English.

“Too” is an adverb and means also, “also.” “To” is a preposition; viz; I am writing to the editor; I am going to the market; I am listening to music.

Comma is optional.

If you said, for example,” I want some that are too big,” then “too” means “excessively.”

So “I want some, too” removes any ambiguity.

I second gail re your skills with English.

Too = ‘for’ (meget) or ‘også’
To = ‘til’ or ‘at’

Too late to edit the above, but for me, the easiest way to remember it is: Too has too many o’s to mean to or two.

Is the optional comma considered more formal?

Actually, you can use both depending on the context.
Ex1:
I am looking for cheese. I want some to use as a pizza topping.
Ex2:
Cheese!?! I want some too!

Ex3: There is too much cheese on MY pizza, too (as well.) I’d use the comma, but it seems to be optional.

Retort: Too bad = Tough luck.

too

Want some what?! Fuck it. I’m down. Count me in.

I think of my two too’s similar to the above. Too=also, many etc.
To=conveyance or movement. I’m not sure if that is an accurate way of looking at it.

I often mix them up & have to really concentrate on it. And, I’m a native English writer/speaker.