Ok, here's another neat trick about the GDP. We do not measure growth of the GDP in nominal values, but real values, aka, we adjust for inflation (yes, this is the _only_ case where you can actually "adjust for inflation" and will be valid). We use something called deflator which allows us to ignore the variances of value in the currency due changes in monetary policy.

So, the government can "print money" (that's not how it works), which would cause inflation (aka, the currency loses value), so the effect on the real GDP is muted. There's another thing that happens when the government goes into a spending spree which is "crowding out", basically the government buys what households and business would have bought and therefore they don't buy anymore, so the effect of the GDP is muted. There are many other things that happen also due such actions that would actually make the GDP to contract!

Anyways, reckless fiscal policy alone doesn't "manipulate the GPD values". Economies do not work in a vacuum. There's tons of interactions that are not explained because it's too complex to do so without the previous knowledge, to do so in a short amount of hours would be very dangerous because you would think you understand things that you really don't understand. Take a course of macroeconomics, of about 100 hours, and it would only be the start. Then industrial economics, economic policy, taxation, international economics, monetary policy, monetary economics, you get it?