Zoom Meeting Co Hosts

Welcome to the Zoom Community, @bryson.

Unfortunately, no.  You cannot "pre-assign" cohosts.

If they have Licensed accounts and are on the same organizational account as you are, you could assign them as Alternate Hosts, which would allow them to start the meeting without you.  Unfortunately, as the Zoom Support article on Alternate Hosts mentions in the Limitations section:

• If the original host joins after the alternative host, the original host is given the option to reclaim host-control of the meeting, or have the host-controls remain with the alternative host. If the original host retakes host control, the alternative-host is demoted to a participant.

I believe this also means that if the alternate host joins after you do, they enter as a participant.

See: https://support.zoom.us/hc/en-us/articles/208220166-Designating-an-alternative-host