See these links that help to get started with Keil MDK 5:
( current version: MDK 5.38, released: 2022-11-21, https://www.keil.com/update/relnotes/MDK538.htm )
1. Download: http://www2.keil.com/mdk5
2. Getting Started:
https://developer.arm.com/documentation/KGS1/latest
https://www.keil.com/support/man/docs/mdk_gs/
3. Video Tutorials: http://www2.keil.com/video
I recommend starting with: „Setup Arm Keil MDK”
4. Learning Portal: http://www2.keil.com/mdk5/learn/
5. MDK Editions: http://www2.keil.com/mdk5/selector
6. MDK Community Edition: https://www.keil.com/pr/article/1299.htm
Note: The MDK Community Edition has no code size limits and supports all non-commercial use cases!
7. Supported Devices: http://www.keil.com/dd2/
8. Access to supported product versions (for registered users):
https://www.keil.com/download/product/
(Note: Eval-Users do have access to just the latest release of Keil MDK 5, see 1.)
9. Legacy release of Arm Compiler: What should I do if I want to download a legacy release of Arm Compiler?
10. Online Manuals:
http://www2.keil.com/mdk5/docs and https://www.keil.com/support/man_arm.htm
11. Search the Keil Knowledgebase: developer.arm.com/keil-search
12. ULINK Debug Adapter family: http://www2.keil.com/mdk5/ulink
13. Our customer portal: http://www2.keil.com/support/silver
14. Licensing solutions: Licensing User's Guide (arm.com)
15. Our distributors: http://www.keil.com/distis/
16. Arm Virtual Hardware: https://www.keil.com/pr/article/1298.htm
17. Arm University Program: https://www.arm.com/resources/education/education-kits
Note, your local distributor is offering a 30 days limited Keil MDK Professional license key free of charge:
http://www.keil.com/distis/
This i.e. allows to gather experience on Keil Middleware components:
https://www2.keil.com/mdk5/middleware