[I am not a teacher.]
1. When the pronoun is the subject, use 'I'.
eg. I love you. (subject: I; predicate:love; objective: you)
eg2. Sandy and I went out for a meal last night (Sandy and I is the subject of the sentence, so you must use 'I'.)
2. When the pronoun is the object, use 'me'.
eg. You love me. (subject: you; predicate:love; objective: me)
Now pop quiz, let see whether you understand it.
Give__ that book.