Translation:The gentleman wants to try on those shoes.
07/17/18. Reflexive verb and, because one is using here an infinitive reflexive verb, this form (with the reflexive pronoun tacked on to the end of the verb) is mandatory. See www.fluentu.com/blog/spanish/spanish-reflexive-verbs.
Señor can be translated as "lord" in the sense of "a man who rules over something". If you mean the specific title for a British nobleman or member of Parliament, which would be the likelier interpretation if you start with "The lord wants ...", it would also just be called lord in Spanish.
In British English, if this conversation was taking place in a polite or up-market estblishement, you would normally translate "El senor" as "The gentleman", however there is far less deference towards customers these days and you would more likely hear something like "This bloke", you wouldn't ever use the term "Lord", unless the customer was actually known to be a titled.