As a rule I allow at least 1 hour's flight planning per hour's flight. . .A two hour flight should have at least 1 hour preflight activities and allow 15-30 min post flight activities. So, that is now about a 4 hour day. This doesn't include transport to the airport. Add on the study you do for the exercise and you have a 6-7 hour day. . .A tip, don't waste too much time getting on the turps etc with the CPL. You have plenty of time to do that after you have finished. Think of how much this is costing and remain focussed.