I previously spent a lot, and I do mean a lot, of time on bluetooth and can tell you, there are precious little decent tutorials on the web.
Sure you will see the same old ones on Carwhisperer being used outside a coffee shop and some bluetooth sniffing, but in reality, this was done on old model phones and any phone you have
nowadays will not allow a "forced pairing" like you may have seen in Person of Interest or the like.
It may well be the case that tool updates are improving the current capabilities, but I have yet to see a modern phone that will accept a pairing request without requiring user interaction.
Although Bluetooth is a very fun topic, I fear you will find precious little new information.