Welcome to the group! I also give you very high marks for parenting as many would not do what is really needed to support their child. While I don’t have specific experience with this situation, I can share some things about social transition as I have essentially socially transitioned (M>F).
Social transition is largely about the visuals and deportment. Looking the part is very helpful.
Visually, typical clothing of 14 year old males is about where you want to be, stylistically and in terms of color. The idea is to fit in.
In terms of deportment, things like speech (tone, cadence, inflections, etc), body language and gestures come into play. Observation, in general, should be very helpful. Perhaps some difficulty comes in because you want to give the impression of just being a regular male and not an effeminate version. That would probably bring some unwanted scrutiny.