No need to create two separate wallets, with separate seeds, unless you really want to.
I think it is better to create your wallet in private, on a computer that is not and never will be connected to the internet. Write down your seed by hand and keep it in a very safe place, or memorize the seed and destroy any and all copies of it.
Then export the "Master Public Key" to a usb thumb drive, then create a "watch only" Electrum wallet on an online PC using the "Master Public Key".
That way, you can use all the public keys you want to receive bitcoins, but will not be able to send any bitcoins from that wallet unless you first create an unsigned transaction to a file on a usb thumb drive, put that drive into your offline only PC and sign the transaction, then bring the thumb drive back to the online PC to send it.