Career shift into ServiceNow

Hi- I've been working in IT for 20+ years - mainly with ASP/VB.NET and SQL Server technology. I've been interested in ServiceNow and have been working on it on the side. I have a PDI- and have also taken a couple certifications like CSA and CAD. I'm looking to get my foot in the door into the ServiceNow realm. What can I do to help with this? I'm considering taking the CID-DF exam(since the first attempt is free). Have heard this is a tough one. Should I take this, as it'll get me a good foundation in CMDB? Would appreciate any tips. PS- I am a US citizen.