Why sandboxes matter
Infrastructure skills are motor skills. You do not learn the shell by reading about the shell, and cloud services only make sense once you have created one, misconfigured it and watched what happens.
The obstacle used to be cost: a cloud account meant a credit card and the risk of a surprise bill. Several providers now solve this with time-boxed sandboxes attached to their free training.
Where to find them
Microsoft Learn attaches free browser sandboxes to most Azure paths, so you can provision real resources without a subscription. Cisco's introductory Linux and networking courses run entirely in the browser, including a network simulator. Kaggle gives every notebook a free GPU allocation each week, which is more than enough for an introductory deep learning course.
- Microsoft Learn — free Azure sandboxes on most paths
- Cisco Networking Academy — browser labs and Packet Tracer
- Kaggle Learn — hosted notebooks with weekly free GPU hours