Agree with your sequence of steps as to complete upgrading to 12.2, the db should be @ a minimum of 188.8.131.52.
I would advise you to review below docs, that should help you and have a better understanding:
Interoperability Notes Oracle EBS Release 12.0 or 12.1 with Oracle Database 12c Release 1 (184.108.40.206)(Doc ID 1930134.1)
So, you could start with the db upgrade as Step 1.
12.2 -- Install & Upgrade
Useful 12.2 Documents (Doc ID 1585889.1)
Oracle E-Business Suite Release 12.2: Technical Planning, Getting Started, and Go-Live Checklist Note 1585857.1 (Very useful doc)
Oracle E-Business Suite Installation and Upgrade Notes Release 12 (12.2) for Linux x86-64 Note 1330701.1
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