Ordinarily, a contribution occurs when money or anything else of something of value is contributed to a candidate. This includes contributions of other goods and services, including the use of space to host campaign meetings and rallies.
There is an exception for when a volunteer secures the use of a church or community room for a candidate function. No contributions result when someone secures the space, provided that the space is used on a regular basis by members of the community for non-commercial purposes. In addition, the room must be available for the use by members of the community without regard to political affiliation.