It is simple, Just Open Your Map And Hover Over The Locations Of Towns And It Will the stars to you, they aren't that hard to find.
You Have To Beat 2 Tournaments, 1 for each Star.

It's Way Down On The Map As Seen On The Screenshot.

The Trick Is Simple As It Gets. Just Spam "All-in", Keep Spamming It If You Lose 1 Or 2 Hands It Is Fine. As Long As You Keep Spamming "All-In". You Should Beat Them This Way. Cause They Are Cautious Players And They Hate To Risk It.

As You Can See In The Above Image. I am On Fire And Got 2 Trophies For Not Losing Any Chips.

Same Stratgy As The Gold Mine Brothers ( Go All-In ) and u will easily win the Oilfield.