I see no reason to say NO. Anyone who tells you that this is impossible is either just mocking you or doesn't understand or is lying.
It is possible to start a career with freerolls, and I would even say it is correct. The fact that you start your career with freerolls does not mean that you will not end with them 🙂
It is possible,I have never made a deposit and I have been playing poker for almost twenty years.I buildt my bankroll and got experience playing using freerolls and it has been a great poker journey and it still is.Pot odds I learned from Dan Harringtons poker books, It will help you win in the long run and deal wit statistical fluctuations like bad beats.