Yeah I wouldn't rely on the stats that those sites give you, the DFS games are all about differentiation. You pick the 4-5 big hitters that everyone has (i.e. Mike Evans/Zeke Elliot last week) who have favourable match ups and are scoring consistently.. then try and fill the rest of your team with cheaper punts who are might be filling in for injured players.
Unless you're just lucky I'm afraid the NFL daily play sites require quite a bit of homework to stand a chance of grabbing a prize. Check out www.fantasypros.com
as well as it consolidates all of the fantasy advice in one place so you don't have to go hunting all over the internet for it.
Oh and try and stick with the 50/50 games while you get the hang of it as they offer a higher chance of winning