At the moment it is especially difficult to find work for the students that have just graduated and have no experience. Don't despair if you can't find a job immediately. Strive for success, and sooner or later he will come to you.

If it's an invitation for an interview from a company in which you might want to get a job, carefully prepare a response letter. Write it free form, without too much official that will create between you and your employer a simple and trusting relationships.
Write the answer in the following form:
"Dear .... (here enter the name and initials of the person who wrote you the letter the invitation to interview)

I received your letter.

Thank you for the invitation. I will be at a specified time".
Please put your signature.
This concise and succinct response to the invitation to the interview will create a good reputation at the company where you want to get a job. Send the letter the next day after receipt. In any case, do not send the letter immediately after receiving, create the impression that you're contemplating the decision, weighing the pros and cons. On the day of travel to their employer put on your best business attire and groom yourself in a proper form. After all, the first impression about the applicant is often a determining factor in hiring.
At the interview, behave calmly, clearly and concisely answer questions posed to you. Thus, you will create a good impression about yourself. Prepare in advance to all possible questions that might be posed or asked. And consider them the most successful and correct answers that will please your employer. Do not worry if you are unable to pass the interview at the first company you came to get a job. Gradually improving your skills and abilities, you will soon find a place of work that will fully reveal all your capabilities.