Can’t decide on a head coach..

Last year my PT and I thought of opening a gym I promised her to be the head coach, she traveled and left me struggling with the gym ,because I have no experience in gym and what it’s need, and every time I asked her question (WhatsApp) she said I don’t know because I have to see the place or she will send me articles to read or videos to watch.. during this time I met another coach who offered to help me without asking for anything. She helped me with the design, name,equipment, color,.. now the coach who helped me quit her job , because the gym she is working at said that they will pay her less than what they agreed on , she came to me asking to be the head coach if the other lady is not coming, I agreed because she was helping in everything from the beginning, and I told the first coach that the head coach position is taking now .. Now I feel guilty because I told the first coach that the position is taking , and I would like to know if what I did is right or wrong??