I usually advice against going solo through the immigration process. The thing is that there are so many little things that can halt or delay the application that yes, in the end you will be able to do it, but it won't be easy. I have several examples, starting from myself, where fluency in Spanish was not enough. And if you are not fluent in Spanish you better forget it.
Just to give an example of how things work, even if totally unrelated. I grew up in Perú and have lived in south america for 30 years, but I am Italian: if I enter a store and they ask me for my nationality and I answer Italian, chances are that prices will be pretty high but, if I answer Peruvian the prices drop significantly. My wife is Italian and speaks very little Spanish: of course, if she asks for a price usually it will be 15-20% higher than if I do the asking, with peaks of 100%.
In this country you must be fluent in Guaraní and have friends, as I explained it in another post in Italian, otherwise things can become difficult: obstructionism was invented here.