Welcome to the Zoom Community, @jlcbeck.
You want to use the Join before host feature. Here's the Zoom Support document that describes it in detail:
https://support.zoom.com/hc/en/article?id=zm_kb&sysparm_article=KB0067063
A simple summary
Essentially, locate (and if desired, edit) your Host Key from your profile on the Zoom Web Portal. Set your meeting up with
- a Passcode (required whenever Waiting Room is disabled)
- disabled Waiting Room
- enabled Join Before Host (I recommend 15 minutes)
Give your Host Key to a "substitute host", who will enter the room and use the Claim Host menu to become the host. I don't recommend giving this out to all attendees... just someone you can trust to be host when you're not there.
Note that with Join Before Host properly enabled, the meeting can continue even without a Host.