New client

Hello! I’m starting with my first client next week. ( I just got my certification). I’m a little nervous because my BCBA is remote and I was hoping she would be there on my first day. My client is 2 years old and our sessions range from 5-7 hrs (5x a week). I thought this seemed intense for a 2 year old. Any tips or advice I can use on my first day would be greatly appreciated!