Here's some general advice:
Before developing a plan, you need to determine exactly who your buyer is. Then, based on their role, understand where they are in an organization chart, etc. Important - this is the same as complex enterprise sales in the private sector, so the info you get in Alchemist is directly relevant even though we're talking government.
Governments vary too much to generalize re: what's a good city to approach vs. what's a difficult city.
Your price point will determine your sales process. Is it expensive enough that it goes into the budget or inexpensive enough that people can buy it with discretionary funding?
Check out existing resources like GovTech magazine, CoProcure, etc. This link looks decent: https://blog.close.com/how-to-sell-to-governments.