depends if you are afab or amab
if you are afab, I would suggest staying in the closet or saying offhand "I like they/them pronouns... could we try them out for me?" to test how transphobic they are
if you are amab, do the they/them thing, and if they are chill about it, ask for she/they as well
I don't know how helpful this will be, but thats kinda what me and my friends did/do. (my parents are kinda homo/transphobic so it didnt work out for me tho haha)
love ya!