Mastering the pronouns in French can be difficult, this is why it is important to take the time to work on them and practice with exercises.
Have a look at this course and start mastering them:
https://www.french4me.net/courses/1416527
Here are the lessons that you will find there:
The COD pronouns (10:00 )
Les verbes transitifs #1 (8:27 )
Les verbes transitifs #2 (7:05 )
Les verbes transitifs #3 (7:21 )
Les verbes transitifs + intransitifs (8:24 )
Les nuances avec les pronoms COD (12:52 )
1 pronoun in affirmative imperative sentences # LA (2:11 )
1 pronoun in affirmative imperative sentences # LES (2:23 )
1 pronoun in negative imperative sentences # LE (2:55 )
1 pronoun in affirmative imperative sentences # LE (2:25 )
1 pronoun in negative imperative sentences # LES (2:55 )
2 pronouns in affirmative imperative sentences (1:39 )
2 Pronouns in negative imperative sentences # LE (1:37 )
2 Pronouns in affirmative imperative sentences # LE (1:30 )
2 Pronouns in affirmative imperative sentences # LA (1:33 )
2 Pronouns in negative imperative sentences # LES (1:31 )
2 Pronouns in negative imperative sentences # LA (1:37 )
2 Pronouns in affirmative imperative sentences # LES (1:28 )