I don't have any of these devices (Set up HomePod, HomePod mini, or Apple TV as a home hub) so my question is, can I use Alexa for my home pod?

can I use Alexa for my home pod?

No.

Setting up HomePod Mini requires Phone, iPad, or iPod touch, See Set up and use HomePod mini and HomePod

If you are using an iPhone the specifications state it will need to be iPhone SE, iPhone 6s or later, or iPod touch (7th generation) with the latest iOS.

However, once a HomePod is set up you can use Alexa for Apple Music (see Play Apple Music with Alexa) and for podcasts (see Play Apple Podcasts with Alexa).

Alexa is a virtual assistant and if you set up a HomePod, Siri will be the virtual assistant for that

Your question isn’t clear; you say you haven’t got a HomePod set up but can you use Alexa with your HomePod?

if you’re calling an Amazon Echo “Alexa” then yes you can use some smart accessories with that but they need to be supported by an Echo. HomePod supports “HomeKit compatible” accessories.