Yes, you can use the Alexa app for simple control of devices. You can also create Hubitat web-based dashboards that are accessible when away from home as well.
Hubitat does not have native Ring integration, yet. However, I actually use my Ring Doorbell with Hubitat by having an Alexa Routine (created in the Alexa app on your phone) triggered by my Ring Doorbell Motion (you need to have the Ring Skill enabled in the Alexa app on your phone for this to work.) In the new Alexa Routine, I have it turn on a momentary Switch/Motion detector virtual device using a virtual driver that I wrote for Hubitat.
The Hubitat device needs to have both Switch and Motion capabilities. The Alexa Routine simply turns ON the virtual device. The virtual device sets its switch attribute to 'on' and its motion attribute to 'active' for 3 seconds, and then changes them both back to 'off' and 'inactive' respectively.
You can then use Motion Lighting, Simple Lighting, or Rule Machine to have any light in the house turn on, and then automatically turn back off after two minutes. This setup has been working extremely well for many moths now. Using Alexa as a bridge between the two systems is much faster than trying to use IFTTT.
Similar to what @ogiewon mentions, I integrate my Ring doorbell by using an Alexa routine to turn on a Hubitat virtual switch. This triggers a Rule Machine action to turn on a light, then turn it and the virtual switch off after N minutes.
Hubitat has half an app, sorta. You can create one or more dashboards that will allow you to operate devices and/or see their status. Those dashboards -and only those dashboards- will be cloned on the hubitat cloud. So, yes, you will be able to do away from home actions & monitoring. What you cannot do via the cloud is access the Hubitat programs you've created to change -say- a lock pin or time of day to operate, etc. I don't do it yet, but there are those here who vpn to gain remote access for that type of control.