Plan well to build well - because there is no right way to build the wrong thing! Do a feasibility study:
“We did find a strong correlation in overall satisfaction with the building project if a feasibility study was conducted. The disappointment however is that only one-third of the churches conducted a feasibility study.” (Rainer Group Study 2005)
Objectively determine what you need to build, what you want, what you can afford, and how you will pay for it before you engage an architect.