Here are some ways to work toward those goals in each case.
First: Certainly, you can become a missions advocate and activist in your church. Perhaps God has stirred your interest in missions, in part, to bring you into a supportive role or get involved in some way. If your church has a missions committee or team or board, find out who they are and how they operate. Maybe you could help with some of the work of the missions team. If your church does not have a functional missions group, the Lord may use you to get one started.
Second: You need to find out what your church supports, why they support those ministries or people, and what is the process of having your specific interest approved. It may take considerable time and effort on your part to learn, communicate, and move the decision process through to completion. Be a part of the solution, not becoming an irritant to the decision making. You might actually have to grow in discernment and diplomacy as part of it.
Third: Inform the church leaders and submit to their authority. It may mean that you need to invest in equipping and enabling them to understand missions. Call Propempo to help! Start learning and studying all that is necessary to be well equipped and qualified to go. Use Propempo resources to help you! Begin building relationships with people and learning from godly mentors as you grow in order to go.
Fourth: Be p-a-t-i-e-n-t! Communicate with your church leaders. Humbly accept their counsel and guidance. Follow whatever protocol is necessary to be fully qualified and sent from your church.