You can't! Period. Not because I said so. Because Jesus said so! it is not your decision to start one. It is Christ’s. It is He who said, “I will build My Church” (Matt 16:18).
Now, perhaps you are called to lead a church. I am just saying that you can't start you own!
“But I prayed about this and God has shown me and others many signs that confirm this calling.” You may very well be called to be a lead pastor, but starting a church independent of the Church cannot be what God is calling you to do.
I respect very much your honest and sincere conviction that this is true. But allow me to say several things.
1) I wonder if you might be confusing your general call to ministry and your giftings as a pastor, with a perceived call to start a specific local church.
I am sure that many others around you have come to you and supported your convictions; including men and women who are mature believers. In addition, things are unfolding around you that confirms that it is the work of God: a building has opened up; resources have become available, people have volunteered to help with ‘x’, ‘y’, and ‘z’, etc.
But realize first that many others have had the same convictions and signs from God, and have failed miserably. Now, I affirm that failure is not necessarily a sign that God did not call a person. God sometimes calls us to things that will “fail” (in such instances “fail” is a matter of perspective). The point is that such persons were convinced that they were going to build the next successful church, or even megachurch, and it never happened.
2) how many of the people around you that are confirming your call are really adequately trained in Scripture, church government, the history of the Church, theology, etc., to provide this level of counsel?
They may, and in fact I am sure they are, godly men and women. But people can only counsel from the resource of knowledge that they have. If they themselves do not have the adequate training necessary to process all that goes into such a decision, then they cannot possibly provide an authoritative response.
(I realize that I am likely upsetting a lot of people here. And I am sorry. That is not my intent. To use an analogy: a corporate executive should not come to a person who has worked their whole life as a nurse, regardless of whether or not she is a mature believer, and seek advice on how to most effectively move one’s company through a merger. This nurse simply does not have the necessary acumen to counsel in such matters. She may be able to counsel the corporate exec in regards to handling her personal conduct and Christian witness. But she cannot counsel in regards to the nature of running a corporation).
Now, does this mean that one cannot seek godly counsel from other Christians? God forbid. Indeed, in the presence of “many counselors” (Prov 15:22) there is wisdom.