I am new to Dev Central. 2 things I am looking for
1 - How to create custom WAF policies and if possible how to test it? Where WAF logs will be stored?
2 - How to monitor F5 appliance in Azure and how to generate email messages / SNMP so we can get the alerts for e.g. CPU, Disk Space, Memory etc?
Looks like you have zero knowledge about ASM, you should start from reading this article:
Part 2 is talking about Policy Building.
F5 appliances can be easily integrated with SNMP monitoring, all documented and guides available, here is one:
Hope this helps,