Hello Cehoatooss47
Firstly, good day and welcome to the SBB Community.
If you purchased a seat reservation, you could find your seat reservation in the e-mail inbox, just as your ticket, too. The seat reservation would be in a separate e-mail. If you purchased the ticket & seat reservation as a registered user, it is available in your account > My orders.
If you do not have one, never mind, it is not necessary; read this:
https://community.sbb.ch/blog/23887-demystifying-seat-reservations-on-swiss-trains-a-comprehensive-guide
Kind regards,
Roland