What do you do to get a hobby phone?
A "hobby phone" is just a short hand for saying any disposable, usually pay-as-you-go cell phone. It's usually not connected to your real life in any way, and you can simply throw it away in the event something happens. It's also not attached to your real life phone records, etc. should you need that level of discretion.
Any big box store that sells electronics will have multiple models to choose from.
More technically-minded folks may also use a service like Google Voice to have a "hobby" phone number and access.
I got mine at Walmart paying cash. The biggest mistake that I made is that its hard to chat on the cheapest non-smart phone. On the good side, the batteries last a long time. (especially, if you turn it ON only when you need it). Highly suggested if you call phone# on ads.