Great advice there from Pilot DAR!
I would also advise you to ask an experienced pilot if you could shadow them while they plan/prepare a flight. You'll have to be careful not to distract them, nor to take too much of their time, so it might be best to do this just as an exercise at first.
As they check weather, NOTAMs, prepare the map, calculate weight and balance and fuel/performance, take notes or ask questions directly about what they're doing and what knowledge they are using to interpret and use the information presented. That might point you towards some areas of further study which you might then find easier, as you will have some idea of the practical application of the material.