We should pay to address "3Bfhey" (who is address) does that is address generated by system and will be work automatically ?
You should absolutely
not pay this address. We do not know who owns this address. It may or may not be owned by the person making the video, or just be a random address they picked as an example. If you send coins to this address, then you will never see them again.
This video explain about how to lock bitcoin and spend it. But I didn't see where the bitcoin go(I mean like address shown on video 1.)
Timelock transactions do not "lock" bitcoin and make them unspendable until a certain time. They create a transaction which is not spendable until a certain time, but there is nothing stopping a different transaction being created and spending those bitcoin in the meantime.
Can you explain what it is you are trying to achieve here?