Firstly I would like to congratulate the person who has decided to own the business by investing and there by breaking the barriers of traditional investing. 

Because it is said that “Generational wealth starts with one risk taker”, and you are the one who is laying foundation for wealth creation and pass it down to next generations. 

How to pick a stock or a multibagger stock?? Is the question often cracks the heads of people who wish to invest in stocks. But before this, a Long term investor should understand he is investing in a business which he will own once he buys the stock from market, so one should be clear that you are owning a business and not a mere stock. 

So some important things an investor should consider when picking a right business (stock) are:

1. Past Performance (chart) : Long term performance chart of the company over the years is one of the best indicators that shows how the company has performed in the different time periods, how it has reacted to the bear and bull markets.
2. Holdings of DII and FII: The percentage of Holdings owned by the Domestic Institutional Investors like Mutual funds, Banks, insurance companies, NBFC and other investment companies and the Foreign institutional investors indicate the trust of qualified professionals in that business and management of the company. Higher the holding of these investors is a good sign for retail investors to enter.
3. Long term Borrowings: just check whether the company is debt free or if there is any debt, if the company is debt free like IRCTC, HDFCLIFE than it's a great news for investor and if it has any debt check whether it is in decreasing trend or not. Decreasing trend in debt year on year indicates the company is paying it's dues on time and has not defaulted.
4. Cash and Cash Equivalents: see the status of cash and bank balances whether they are improvising on it yearly or not.
5. Promoter Holdings: A promoter is one who is associated with the company from the beginning or we can say promoters are the founders of the company as they are responsible for raising the capital initially. Significant holding of promoters say 30% or more is a sign that promoters are confident on this business and they are the ones who will have best information of business. This is why it is important for investors to track promoters holdings.
6. Products and services: do u love to eat Dominos pizzas?? If Yes, then how about owning it, why don't you consider buying jubilant foodworks stock. Do you travel often with railways?? From Where do you book tickets then?? IRCTC oh! Why don't you consider owning it. Always check out on the products and services offered by the company and whether they are promising or not, whether they meet the customer expectations and satisfy them.
7. Management:  Board of Directors is the governing body of a company which sets the direction for the company, so it becomes necessary for the investors to know about the people sitting in the Board, their qualifications, experience and achievements.
8. Investors should consider whether the business is promising or not, how they have performed over the years, what is the major source of revenue for that company and whether the circumstances for such business will be favorable in the future or not.