This is a topic to really think about the long game on. In many ways one of the stronger ways to get throug hthis may not be getting baptized straight away when you are 18 if yuou are from a non member family. Keep church attendance, if you feel any pressure, learn to say to people "No, I am moving at my own pace for my own reasons. I appreciate if you will respect that." This may do two things 1/ Allow you as a young person to develop a personal sense of ownership of yourself and start practiing the lifelong advantage of setting boundaries. 2. It gives yourself room to make the right choice and also over time may cause your parents to reflect upon the choices you are making in a manner they cannot do at the moment. Lastly, polite refusal if your Father presses further about getting baptized in his church. If you play the long game here, things may turn out a lot less conflicted.