You definitely don't need to talk. At my grandmom's funeral last year I was asked to do a reading and agreed to it because I didn't want to say no. When the time came for me to get up, I just couldn't do it. Luckily, a family friend took over and did it for me. Everyone deals with their emotions and grief differently. If you don't want to talk, don't do it. I don't regret it and I don't think you will either.