Practical Magic (1998) used downtown Coupeville, Washington, as its small town, per Wikipedia. Coupeville is a Victorian-era seaside port town on Penn Cove on Whidbey Island, and its downtown is public and free to walk.
The Owens family house, however, was built for the shoot on San Juan Island and demolished afterward, so there is no house to find. The local tourism bureau markets the connection on its Coupeville page; check its events calendar for seasonal walking tours or festivals, since specific dates could not be confirmed.
See our Halloween movie filming locations guide for other Halloween-season sites around the country.