Where should I start learning Azure and Azure Stack?

Start with the Azure Fundamentals material on Microsoft Learn. It gives you a structured introduction without requiring you to pick a specialty straight away. You can use the certification topics as a study plan even if you don't intend to take the exam.

After the basics, decide whether you're more interested in development or infrastructure. That will make it easier to choose what to study next instead of trying to learn every service at once.

Get into the portal alongside the reading. Pick a small exercise, build it, see how its pieces connect, then delete it and try again. For example, you could explore Azure Files, virtual networks, and private endpoints together.

If you use a trial or pay-as-you-go account, check the current credit and account terms first. Watch your spending and clean up resources when you're done. Leaving things running can use up credit quickly.

For videos, look up the Azure tutorials from John Savill. They can be a useful companion to Microsoft Learn if you prefer hearing concepts explained before trying them in the portal.

For the Azure Stack side, take a look at Jumpstart LocalBox, which was suggested as a resource for Azure Local. I'd still get comfortable with Azure fundamentals first, then check what that project covers and what it needs before setting up a lab.