"The first impression is the last impression" 
Literally, in few seconds, we create our impression on others. It, in turn, necessitates the need to prepare well to build a solid impression on the interviewer. 
You have been hunting for jobs on social media, job portals and many other platforms. Among those, you may have liked few companies where you probably have shared your resume. Now that you are stressing over the interview. Here's a list of do's and don't while giving an interview. 

Before the interview: 
If you are giving the interview, it's essential to research the particular company in detail. Plan to position your skills in accordance with the company. 
Research about the company's image and health. Is the company capable of meeting your requirements?
Linkedin is a professional platform. You can inquire about the company with your contacts on LinkedIn. 
Research about those who will be taking your interview. 
Have a detailed analysis of the job you are interviewed for. Prepare yourself by practising and be clearer with your thoughts by asking the interviewer if you have any queries. 
Think of your previous achievements where you managed to accomplish the task even under time pressure. Jot down the points where you have been proud of your excellence. 
Explore how much potential you have and deserve how much salary. Research thoroughly if you are underpaid according to the market. 
Pay attention to perks you will receive, such as growth, learning, flexibility, and many other benefits. 

During the interview: 
The first thing to keep in mind is to always dress professionally. No interviewer wants to see you in a casual dress. Dress professionally and respond to everything smartly and energetically. It would be best if you reach before the scheduled time. 
It's completely acceptable if you do not know the answer. Say "NO". 
Either say I need a few moments to think about the same. 
Take a pause to think and then respond 
Don't try to be over-smart, as experienced professionals will instantly catch your lies 
The key to ace the interview is to maintain calmness. Maintain eye contact with the interviewer and smile as it will interviewer know about your ability to handle pressure. 
No matter what might be your reasons to leave the job, never ever say a bad word about the old employer or a manager. 
Ask the recruiters your doubts and queries, for example- the work environment, perks of joining their company, flexibility and much more. 
The interview is conducted for both parties and to check whether the candidate is capable of the job. 

After the interview: 
Inquire about the timeline you have to wait for after the interview is completed. Follow up with the recruiter to know the status of your application. 
Whether the results are in your favour or not end the conversation with a positive note. 
Always remember the interviewer isn't interested to know more about your resume but instead about you as a person.