Marriott Vacation Club Resale

If I buy a resale property in medium season how does it trade with II? Can I use points to stay at Marriott hotels? Is it hard to exchange into other MVC Properties. I’m looking at Newport Beach

If you buy a resale you then enroll it in II and pay the II fee. Resales don't give you points. Those only come with new sales. To exchange with other MVC properties depends on the demand and the dates you want. If you are looking at high season, you would need to put in an exchange request as soon as possible.