A TON OF/TONS OF is a large number or amount (informal):
e.g. all of a sudden I had tons of friends (friends - countable)
they bought tons of fruit (fruit - countable)
I've got tons of time (time - uncountable)
there is a ton of salt in the ocean. (salt - uncountable)
xiaokaoy, as you can see these words can ce used both with countable and uncountable nouns.
These words can be used both with COUNTABLE AND UNCOUNTABLE nouns:
no some enough lots of plenty of tons of loads of
TONS OF =much; a lot
e.g. He's in tons of trouble. = He had a lot of problems.
We've got tons of them. = We have got plenty of them.
I’ve got tons of things to do. (= a lot of things to do)