Well, I thought I should give another view.
I’m 41, have started one company, being self entrepreneur for long time and also was CTO for some country leader companies before starting my current new venture. I have failed several times until I discovered something that has helped me a lot in the recent years.
Think that building a company means not only creating the environment to develop your technical skills and produce something, but to sell and generate cash flow. At 20s, you don’t matter much about real business but to show your technical skills. At that age I recommend to learn from key succesful companies, work for them and observe how they operate the business not just how they build products.
The main requirement for building a company in the end is to have the conviction that you can create and maintain a stable and growing stream of income.
Having the skills to operate the technical aspects of the company is obvious (development, administrative and financial) but you lack from business experience.
Before starting a company evaluate your desired potential market and how to succesful reach it (sell to them).
Knowing that market is critical to understand why they will purchase your products (price, value, competitors).
Knowing how to reach those customers is critical to close the neccesary deals to make the company running everyday (how do they learn about your products in a saturated market, how to stablish conversations with customers and keep learning about how to provide more interesting products and services, are you selling to a publisher or directly to end users, what’s the net income you will be doing…)
Many companies are created from a real previous deal which is the only way to start solid.
Finally if you just want to do it, my advice is to keep your expenses low, don’t purchase anything that you won’t be selling in someway unless you need it absolutely for sure. This your first time and chances are you will fail so don’t get obsessed with it for long time - keep moral high, know that you are learning and ship something soon!
Good luck and enjoy the journey!