You say "I'd like to ___" to let the listener know what your purpose is. For example:
I'd like to introduce our first speaker.
You say this before you introduce him.
I'd like to place an order for delivery.
You say this when you call to order food to be delivered from a restaurant.
You use the phrase "I'd like to (do something)" this way mostly in speeches, or when you're talking with someone like a bank teller or a restaurant host. You don't often use it in face-to-face conversation between people.