I was baptized at one church, but recieved confirmation and communion at another church. Which is my parish?

In one sense, your parish has geographic boundaries, and your parish is the one whose boundaries you live within. However, in practice, your parish is the one you choose to currently participate in. It could be either of these two, or neither of them, depending on circumstances. Obviously if you moved to a distant state, your parish would be neither of these. However, you might choose a parish other than one of these even though you still live nearby.