You did the right thing in confirming via a different method of communication.
Did you tell your friend to change the password for his email just in case his account was hacked? The scammer could have gotten your email from his contact list. However, I see that your Trent account list listed online so it could have been more easily gotten from there.
Therefore, going on I'd suggest not trusting
any emails from a "friend" because everyone that wanted your email already has it: the scammers, spammers and bots.
Also, ask Trent if they really do need to list your email address online. Your Trent number is already there. Someone needing it can call you and get it that way.
The attempt was probably just was to get your number but for what purpose I can't imagine. Do you have any accounts with any websites that ask for your phone number information to either login or retrieve a password?
It seems more likely that he'd be trying what Bill said, wanting to contact your provider, pretending to be you and ask for a replacement sim card and having it sent to them and/or changing your number. Your SIM card doesn't store all the information on your phone. It's only about 128 KB but it's enough storage to
store contacts, phone numbers, text messages, data usage and billing information. But that's bad enough and some sites use text messages for 2FA.
I agree with Bill that you contact your provider. Give them the info of what happened and ask them if a replacement SIM has been requested on your account or your number was requested to be changed. Then ask them to put a lock on your account so that no replacement SIMs, phones or phone number changes for a certain amount of time. A lock that even you can't circumvent.
When you contact them, note what information they require to ascertain your identity. They should ask for
something more than publicly accessible info like name, address, postal code, phone number, email, birthdate.
Also, consider enabling the SIM lock feature on your phone. It will prevent the SIM from being used in a new phone or being swapped in your existing phone without entering a PIN. I suggest you contact tech support while you do this in case of any problem doing it.