How we can start our speech? …

Format for Speech Writing - In order to write a perfect speech, we must be well acquainted with the topic and must possess a wide range of vocabulary, a thorough knowledge of the subject, some research, and excellent organizational skills. Here are the ideal format and tips to help you write your perfect speech.
A perfect speech must consist of:-

1. HEADING- The heading should be catchy and in not more than 5-6 words. You can go as creative as you want with this one just make sure you do not devote too much time to it in the exam.
2. OPENING LINE- This includes salutations, introduction, and the topic. Make sure you do not mention your personal details (name, school name, etc.).

Example- Respected Principal, teachers, and my dear friends! Today, I (the name is given in the question) stand before you all to speak on the topic “(given in the question)”.
OR you could start with a quote related to the topic and then go with the salutations and introduction.

1.  BODY- It is the main part of your writing piece.
2. It is always prescribed that you begin with a short introduction on the topic, it’s meant to be precise. 
3. Then you need to explain the current situation, the problems (if any), and whether after any corrective actions, betterment in the situation has been observed or not.
4. It may include advantages/ disadvantages depending upon the topic in question.
5. Now here, it is important you follow a sequence. It is possible that you have too many points or very few points. When you have a lot of varied points, it is better you choose a few best ones and write a line on each. In case you have very few already, explain them in at least two lines each.
6. You have to strictly follow the prescribed word limit in a limited time frame so just do not go on writing and writing.
7. MOST IMPORTANT- Always begin with your strongest point. You can accommodate the weaker ones in between and end with another strong point.
8. Feel free to give your personal opinion in one or two lines.
9. It is very important that you do not deviate from the topic. There are chances you may get ideas linking from one to another that may deviate you from the main point. You have to refrain from doing so.
10. SOLUTION/CONCLUDING PARAGRAPH- Now, it is to be remembered that wherever you elaborate a problem, you always have to mention the steps being taken to improvise the situation and suggest a few solutions as well.

Now, it would be great if you could add a few quotes relating to motivating the people to take action.
Here also, the rule of STRONG-WEAK-STRONG applies.