It's fine to want to practice with flaps, but first, you do need work on the basics and have them down to where you can do them without thinking about it and flaps just add complexity. If you "need" flaps on a trainer then more landing practice is needed as you are most likely coming in too hot. Trainer do land nice and slow

As Bruce said, basics, basics, basics and what both Bruce and 2slow said, Altitude is your friend.

And I'll add that safety should ALWAYS be your first concern...