1. (optional) Check the online menu and take a mental note of what you want.
2. Go to the counter and wait in line.
3. Find the type of sandwich, bread, and cheese you want. Also check the toppings in case you want extras.
4. Wait for the sandwich barista to acknowledge you, smile, and say "Hello, I would like a {type of sandwich} on {type of bread}, please". You can choose to have it toasted at this point.
5. When asked, mention the extra toppings. If they skip the toppings, you can politely interject with something like "Oh I just remembered, could I also get some {extras} with that?".
6. Check the sauces. When asked, say which one you want. You can also ask for spices like Oregano here.
7. When asked, say whether you want to eat it here or take it away.
8. Pay.
9. Say "Thank you, have a nice day!" to the sandwich barista and enjoy your meal.

Hope this helps!