The Demo as a Measuring Tool
Most guides treat practice mode as a beginner's on-ramp and stop there. Its more valuable role is comparison. Because the payout on a winning call is fixed and identical between practice and real rounds in an honest build, a handful of demo rounds gives you a reference number you can take anywhere. When another build pays less for the same call, you have identified an edited client in about a minute, without risking anything.
That check is worth running every time you open the format somewhere new — a different site, a new install, a link somebody sent. It costs nothing and it inspects the only part of the build that quietly determines what a session costs you.
How Long to Stay in Practice Mode
Until it stops surprising you. That means: you know how long a round lasts, you know what a win pays, you have run the drill twice, and a losing streak no longer prompts you to change your call mid-session. If you reach that point and find the appeal has gone, the demo has done you a considerable favour for the price of fifteen minutes.
For the mechanics behind what you are practising, see the round breakdown on the big small game guide. When you move on, the step-by-step playing guide covers stake sizing and the mistakes that end most sessions.