It is fardh on you to learn necessary knowledge of religion and safeguard your faith and deeds. Read these authentic books i.e. Bahishti Zewar, Talimuddin, Hayatul Muslimin, Jazaul Aamal, Maut ki Yad, gradually and if you read it out before any teacher then it shall be far better.
You should offer Salah and practice other commands which are fardh and save yourself from haram and sinful acts. In short, be steadfast in your religion as well as read the following dua for firmness.
اللهم ثبت قلبي علي دينك
(2) Also supplicate for your father that Allah give him hidayah and give him the true understanding of religion. If you could convince him politely and pathetically then you may do so. Do not go through hot discussion with him. Also avoid doing any disrespect in any matter.
(3) What do you want to tell to all the member of the family, explain it and submit the question again.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband