Know the Difference: Infinitives vs Gerunds - Basic English Grammar

In this video, Alisha answers 5 questions. - My question is: how to use "for" and when "to"? For instance, I want to practice my english "for improving" or "to improve" it? - I have sometimes heard the phrase "just because" as a reply to someone's statement... What does it mean? - Can you please tell me the meaning of "straps in for"? - When I lived with a host family in America, my host mother sometimes asked me "You wanted to help me cook?" Is "You wanted to" the same meaning as "Can you" ? - What does the expression "get it right" mean? I noticed it has several meanings depending on context.