DevOps Newbie - How to automate windows infrastructure deployment?
The first thing I can recommend for you is to remove all of the manual steps in your deployment pipeline. DevOps is all about automating as much as possible to allow for fast, frequent, and safe deployment of your infrastructure. 

Second, if you haven't already, I would recommend using a build and deployment tool (Jenkins, Bamboo, GitLabCI, etc.) to compile your binaries and execute your automated deployment/configuration scripts. Having a central location for your deployments allows you to be able to scale more effectively, avoid repetition, and monitor your deployments more accurately. You should also store ALL of your scripts in some form of revision control ASAP (if they are not already).

Finally, I recommend you read up more on DevOps best practices and how it can affect your organization. In order for DevOps to be truly effective, your entire development team and company must adopt best practices and be 100% on board with a shift in how you manage your deployments. 

Some reading I can recommend are:

The Phoenix Project by Gene Kim, Kevin Behr, and George Spafford

A telling of a fictional, but very realistic story of DevOps transforming a company and the opticals that the team faces to get there. 

The DevOps Handbook by Gene Kim, Patrick Debois, John Willis, Jez Humble, and John Allspaw

Outlines the steps/stages to transform your company into a DevOps organization along with an assortment of real life DevOps transforming case studies.

Accelerate by Nicole Forsgren, Jez Humble, and Gene Kim

A plethora of empirical data and analysis on how DevOps has improved organizations both within IT and the entire company. 

Continuous Integration by Paul Duvall, Steve Matayas, and Andrew Glover

Lays out the steps to take to move your organization to be able to deploy to the highest standards possible.