F2P worth? New to the game

if i were interested in playing the game only as f2p, what would i be able to do? i read other posts... but now the game is only made fun of (i'm not saying it's right or wrong) and i can't really understand what i would find in front of me.

could i do ranked (even sporadically?) would i have a chance of winning against almost everyone if i'm good? is there a possibility to unlock the other characters without paying?