As you can see, people are welcoming here and ready to assist if you're ready to accept it. You're learning that you've gone about this wrong. Sorry for your loss of dollars spent on cloud only stuff, and I want to assure you that's not totally your fault. The marketing for this WiFI stuff (much of it junk) is designed to make you think you can't go wrong by purchasing their product. You can and it leaves you totally reliant on a cloud service that may not be there tomorrow.
On a positive note, you bought from Costco and Amazon, so for the most part you will be able to return these items if it hasn't been too long for their respective return policies. So you have the opportunity to do this correctly from the start! 
If you cannot return them, you can salvage some of the mistakes by using Alexa as the bridge to these devices. You won't get status back into HE when these devices activate, but at least you can activate them.
This post I wrote talks about using the new Alexa custom actions to control devices, but if they are Lights, Plugs, some fans, some thermostats, then you can select those devices directly as the Alexa Routine action.
But do yourself a favor and stop buying the WiFi stuff. Move to Zigbee or Z-Wave devices. If you cannot find the device type you're looking for in the list of compatible devices, ask in the community. There are many devices that people have made work, even though they're not officially compatible. But I would try to stick with the compatible devices and even then I would ask for opinions if you cannot already find them with a search of the forum.
Welcome to the Hubitat Community!
