Question

Hi

Answer 1

You use "it's" as a formal Contraction, it's short for 'it is' or 'it has'.

For example, 'it's a wonderful day's

You use "so" when you are describing something

For example, 'it's so hot'
"So" is also another word for "very", which is where the word originally generated. it's often mixed up with "such", but dont worry! you'll learn English alot soon!