Your intention is too much blessed. It is a blessing for you to take your parents and grandmother for hajj. According to the situation, assume the act which is of relief and easiness for your parents, get yourself busy all the time in doing their service and fulfilling their needs. Seek their advice and always try to keep them content. Obey and comply with them and do not raise your voice above their voice. Always prefer their comfort. For the Masael of hajj get the book Muallimul Hujjaj or Anwar-e-Manasik and study them repeatedly.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband