Both will fall for at least 12 months so neither.
Are you sure that bitcoin will fall for at least a year? How it will happen? Do you have any insider or you have your crystal ball that says it will fall?
you probably just want profit so you should just buy xrp..
Nah, if I'm on the position of OP I wouldn't give any interest on XRP. It's being played by it's centralized market.
I wanna buy some bitcoins now that the price dropped but I heard that BCH is gonna explode soon so maybe buying BCH would be better
What do u recommend me?

Just do what will make you feel happy but if you'll listen to us, majority will say go for bitcoin while it's discounted.