Majority attack – If there are 20 nodes in the network and all receive a transaction, after 10 min.

Question 1) If there are 20 nodes in the network and all receive a transaction and after 10 min, all select the transaction in their transaction pool and start creating a block. All nodes will use the same transactions to create a block, or each node may have a different transaction. in this particular block

Question 2) If there are 20 nodes in the network and all start to create a block, what will happen if several nodes create the block at the same time?