Yes, Hilton Honors is actually free, as there's no cost to be a member of the Hilton's rewards program. Once you're enrolled as a Hilton Honors member, you will automatically be eligible for perks such as free Wi-Fi, guaranteed discount rates, digital check-in, points toward free nights, and more.
Most members start out with the basic "Blue" membership and can progress to higher membership status levels based on how many nights they stay at Hilton properties and how much they spend on their Hilton Honors credit card. The higher your membership status level is, the more perks you'll get when staying at Hilton hotels and resorts.