"Too much" can be used as a measurement for uncountable nouns (most often food words like "food/milk/flour etc etc" - also the grammar in your sentence was wrong - "There is too much food at the party" - so "too much" is used to measure the uncountable noun "food" alternatively "too many" can be used as a measure word for countable nouns - "I had too many drinks at the party"

You would say: there is too much food at the party. 'Too much' is used for something uncountable. However: There are too many flies. They are countable, so you use 'too many'. But there is too much light...uncountable. You would also most often use 'there is/are' before 'too much' or ' too many'.