Tithes and mission offerings go to the Southeastern California Conference to be distributed.  The following website gives more  information on this:

Your Church Budget donations stay at our local church to pay for all church operating expenses, loans and our ministries.

See below to give online:

Adventist Giving

You can make a one-time donation or set up recurring donations.

Another option is to download the Adventist Giving App on your smart phone.