1. So and such are used to intensify the meaning of adjectives and adverbs. So is used before adjectives and adverbs, while such is used before countable nouns or uncountable nouns/plurals.
2. So and such can also be used in constructions with "that" to express a consequence. For example, "the coffee is so hot that I can't drink it" or "it was such a beautiful day that we decided to go to the beach."
3. When combining sentences using so/such and that, so is used before adjectives/adverbs in the first clause and such is used before countable/uncountable nou