نصیحت‌های ضروری برای شروع یادگیری انگلیسی

In this video, Alisha answers 5 questions.
- Could you please explain the meaning of this phrase for me: "A woman twenty years his senior".
- I was wondering, I heard once that the verb "Propose" is used to make a marriage proposal only. I must use the verb "Suggest" instead but I saw "Propose" in several movies for example "I propose we go forward". So What's the truth, can I use "Propose" or not?
- Would you please tell me the difference between the verbs "recognize", and between "admit", "acknowledge"; after I want to know when we use "somehow" and "someway".
- How could I teach English to my kid (5 years old boy) I'm not a native English speaker and I don't live in an English speaking country neither. It'd be great if you can give me some advices.
- Could you help me with the meaning of the expression ""jump on the bandwagon!""?