When you first sign in, a yellow square flashes "FB" over the avatar image on the upper right-hand of your screen to show if you have a free bet available. You can also check if you have free bets in your account by clicking on the Avatar Icon:
Once there you can see your Cash balance, Free bet balance, bonus balance as well as any free spins / chips that are available:
These steps can also be followed on a mobile device, an example of which can be seen below:
Start by clicking the avatar on your mobile device:
This will open a menu, where you can see all of the balances on your account, including your Cash balance, Free bet balance, Bonus balance, as well as any Free spins / chips that may be available: