Don’t hold your breath on lower taxes. Military needs to be built up if we are going to “kick ass”, 2,000 mile wall needs to be built with servicing roads, buildings, surveillance gear, vehicles, cost of screening people coming into US, and unfortunately committed debt—VA, Social Security, national debt, etc. Not much is really spent on other things that can be cut. Here is an explanation of how our 2015 budget was allocated. It goes into more detail than can a pie chart.
https://www.nationalpriorities.org/budget-basics/federal-budget-101/spending/
Not much is really spent on other things that can be cut.
It will take a lot of work, but at least each area should be looked at.
It will take years, but if we get a booming private economy going with lower corporate rates, business mind set, decreased regulations, etc, they may actually have a surplus and will be able to cut taxes. We'll see.