Voice Assistant Robot

Hey guys, I am currently building a companion robot for a school competition and am really stumped on how to get started with hardware. I am using a pi 4 model b, and I need the bot to preform voice recognition and face recognition so I was planning on using a USB webcam. I will also need speakers and a display that will serve as the bots face. Do you guys have any suggestions? It will be very similar to the robot Buddy. Thank you so much! https://www.youtube.com/watch?v=Mpakn6WM03Y&t=122s