I want to know the amount of computational power required to verify a just a couple of transactions. No mining included, just verification can it be done with CPU or maybe even phones?
Transactions can be verified as being valid by inexpensive software, such as a cellphone.
Transaction confirmation requires a miner to include the transaction in a block. Confirmation is not done on a transaction-by-transaction basis, so "how much power to confirm just a couple of transactions" is not really a good question to ask. Instead you could ask "How much computational power do you need in order to mine a block?", with the understanding that many transactions can be included in a single block.