Tax residency

Once you have obtained residency, especially for expats, it's advisable to also apply for tax residency.
Paraguay is not considered a tax paradise, or a tax haven, but it is considered as a low-tax country.

Not so much for reasons in Paraguay, but more for the country where you are/were a tax resident prior to moving to Paraguay. Those countries are often reluctant to cancel your tax residency, meaning that they will still try to tax you, unless you proof that you're a tax resident in another country, in this case Paraguay.

Obtaining tax residency is straightforward, but again most people prefer for a lawyer or an accountant to help them in the process.

As a result, you will have proof of tax residency, and it's even advisable to also pay ( some ) personal income tax in Paraguay, as these documents will show to your former home country that you're a tax resident in Paraguay and you also pay taxes there.