Both of these verbs are used for asking about something or looking for information. The nouns for the request / investigation are enquiry and inquiry.
Technically, enquire is used for "ask" in general ("He enquired about prices for the products"), and inquire for a more formal investigation ("The police will make an inquiry into the alleged corruption.")
However, in American English it is now very common to use inquire for everything: "He inquired about prices for the products."
Be sure to carry extra layers for warmth, particularly an extra base layer long underwear top in case the one youre wearing gets wet from exertion or the weather. Know the signs of hypothermia so you can recognize them in members of your party.