Translation:Pardon me, ma'am, I am looking for a bank.
In English this is a contraction, basically a combination of two words into one or a shortening of a word. An apostrophe is used to represent the removed letters (note that like most things in English this is not universal). Examples include things like isn't (is not), didn't (did not), I'm (I am), ma'am (madam), and so on. There are many such words.
Carolyn, from my understanding, when making a mistake and wanting to apologize in a sincere and direct way, adding the suffix "me" adds that personal touch. So it wouldn't be used to excuse yourself for asking someone directions (as in the example) but could be used if you step on someone's foot (especially someone you know) or forget someone's birthday.
As you already know but for others... Perdoname can be used instead of perdona; perdoneme instead of perdone; disculpame instead of disculpa; and disculpeme instead of disculpe.