Updating a culumn from a select statement

I'm trying to add a new column in my family table called Full Address; It's basically combining values from other columns and generating the Full Address.

I wrote this query but it doesn't seem to be working. Alos, I would appreciate it if there's a better way to generate my desired value, Full Address.

update Family set FullAddress = select StreetAddress+', '+City+', '+State+', '+ZipCode AS Address from Family

Thanks

Presumably, you just want this:

UPDATE Family
    SET FullAddress = StreetAddress + ', ' + City + ', ' + State + ', ' + ZipCode;