Rules to read Bhagwat Gita
Follow the reading of gita with meditation.
Do not read too much of it in one day. (if read too much in one day, you might lose out interest in your actual life)
Read a maximum of two shlokas with their meanings in details.
Prefer an easier version of Gita that can be understood by you according to your language and beliefs
Understanding gita is a slow process. It takes time. You also need to experience and realize the stuff you are reading.
Respect the book. Keep it separately from other books even if you are not religious. This helps amazingly to all the new readers.