The British Council has a page of rules and several activities to practice quantifiers.

The Cambridge Dictionary goes into detail about Much, many, a lot of, lots of.

Woodward English has a few pages describing different quantifiers and their uses.

The ESL Lounge has a short quiz to practice basic quantifiers.

TESOL-direct has a page dedicated to Quantifiers in English Grammar.

BSU has a pdf outlining the use of Quantifiers.

Education First also provides several resources on Quantifiers.