P​‌‍‍‍‌‍‍‍‌‍‍‍‌‌‌‌‌‌‍‍​lease answer the rolling in around 100-125 words each: 

1.Just think of the null hypothesis as whatever you are told is the truth right now. Whatever you read, see, hear, touch, or feel is true. However, you see in life and business not everything is as it seems. What is going on? So, you test the null hypothesis with an alternative. Is it really that way? When you test a new invention or new drug, you set the null up as to say that your invention really does not work. 

Ho: No effect. No difference. The alternative hypothesis is that it does have an effect. It does work. 

H1: An effect. A difference. So, if you retain the null, there is no effect. If you reject the null, there is an effect or difference. The null takes some getting used to but then again you learned how to ride a bike, drive a car and use the internet didn’t you? Once you understand the null, i​‌‍‍‍‌‍‍‍‌‍‍‍‌‌‌‌‌‌‍‍​t will change how you look at the world and you will be able to unlock the secrets of the universe. 

2. If you expand and broaden your study, the work becomes unmanageable. Do not mistake narrow with insufficient or incomplete. The subject must be completely addressed.