Strictly on a pot-odds basis both calls are correct. You are being offered 7:1 on the post flop call and only require 2.6:1 for it to be correct and post turn you are gettng 11:1 and only need it to be 5.6:1.
However, if it were me, I would have folded after the flop. Just call me SuperNit . Why? Well:
1. It is a freeroll and in the early stages of freerolls
I try to avoid multiway pots, particularly ones where the pot gets quite large.
2. It is a freeroll and in freerolls people call, even quite large raises, with total rubbish. With 5 players the odds
are pretty good that even if you hit your set or str8 you will be beaten by a higher set or higher str8.
Still, horses for courses. It depends on your playing style. I am fairly sure that someone will post to say that raising, rather than calling, would be the way to go. That certainly could
reduce the player count although, again, in the early stages of a freeroll that's not guaranteed.