There is no rule against traveling solo.
There is no rule against traveling for the first time.
If you use a visa agent then you should make really sure that you understand what you sign and that it is the truth. Honest visa agents help their clients with confusing application forms, for a fee. Dishonest visa agents enter lies for their clients, but it is the client who suffers if the lie is found out.
Regarding your application, ask yourself if you can reasonably afford the trip, and if someone who doesn't know you has reason to believe that you are no illegal immigrant.
- Who pays the trip and why? In the best case, you can afford the trip from your own income and the cost is just a small part of your annual income. For young people, it could be relatives who pay. Then the questions are:
- Why is the money given?
- Is it really a gift or is it a credit?
- Was the money earned legally? Can the giver afford the gift?
- Do you have a stable job or a stable course of education? It would be best if you earn more in India than an illegal worker or asylum applicant would get in Europe. But they understand that this isn't always the case for young people.