I think introducing yourself is a big one for most people who stutter so you're definitely not alone there. Personally "thank you" is a big one for me. I have very good manners but every now and then I want to say thank you and think about it too long and just give up on saying it. Other than those, giving your phone number to get a haircut (online check-in is a life saver), ordering food anywhere, making appointments for just about anything, people asking me what my dog's name is, giving my address, giving my SSN, birth date, etc. Just have to roll with it!