3) Free 12 months, then pay-as-you-go Azure account subscription (Credit card needed):

You can create your Azure free account. Get started with 12 months of free services. With your Azure free account, you get all of this—and you won’t be charged until you choose to upgrade.

12 months of popular free services + $200 credit to explore Azure for 30 days .

After the free 12 months period, you purchase Azure services with pay-as-you-go pricing. The debit/credit card details must be provided during registration for billing of non-free services.

What you can do with free account? Here are just a few ideas of all you can do with Azure

• Create personalized experiences with AI: Build connected, cross-platform experiences—tailored to customer interactions using AI and machine learning.
• Drive innovation for existing and future apps: Modernize applications. Deploy Windows and Linux virtual machines across cloud and hybrid environments.
• Build scalable apps and release features faster: Create workloads that scale up and down based on demand. Plus, deliver software more rapidly and reliably with end-to-end DevOps solutions.

You can see the pay as you go pricing calculator from this website

https://azure.microsoft.com/en-us/pricing/calculator/