"Hey, if someone can tell me how much tighter a 5c/10c or 10c/20c game is compared to the free games"

I don't think playing them will be worth it (it's basically playmoney). Do the play money games until you are totally comfortable playing online. Read as much as you can. Develop your skills and experience by hitting bonuses. You'll soon have a large enough bankroll and enough skill/experience to move up in limits.