Hey, welcome to the forum.
If you’re running a participation node then you will absolutely be receiving all the transactions propagating across the network, as you may need to propose a block and include them. However if you’re just a regular node you may want to enable the config.json parameter ForceFetchTransactions which will make sure you retrieve all the transactions.
As for viewing these transactions, you can call the /v2/transactions/pending endpoint on the node to get a list of all the pending transactions. As for using wireshark you may need to research that yourself, as I’m not aware of any existing tutorials or guides on using it with Algorand traffic.