If you are using this for work, then these phrasings might help you:
1. "What kind of coffee would you like?"
No need to worry about what/which; use "what". Use the "would like" pattern for politeness. You can also say, "What are you having?"
2. "You can find straws over there on the bar."
I've added a softening phrase ("you can find...") because the basic sentence might sound dismissive. This is much friendlier.
3. "Actually, we don't have iced tea in a bottle, but I can make one up fresh for you."
I don't see any reason to describe the recipe.
4. "Can I get a small coffee and a glass of water, please?"
Do you mean an espresso? Is the extra water hot or cold? If course, if you don't have glasses, then say "cup".
5. Can I get a receipt please?
Again, I don't see any need to explain yourself.
For the buses, I'd say "The triple-one bus doesn't often come this way."