Like Anna said, have a week plan. Start the training with a goal. Personally while training music helps me a lot to keep it going instead of quitting after 25 minutes (which is fine, but a serious training takes longer most of the time)
Have a plan, write out in a planner what exercises you’re going to do on each day. Flat work on Monday etc... Then plan further go set poles and challenge yourself. Also ask your trainer for horsey homework and what you need to improve on and work on it.