You do need to open a bank account with the "magic" $5,000 on deposit (you can withdraw the money upon the residency process being complete.  You must also get an interpol check done here in Paraguay at the Policia Nacional as well as getting a medical check done by a local doctor (lab work, doctor exam).  There is no "order" to these items, you just have to get them done prior to turning in your application and paperwork.  As none of these items take just "one visit" to an office to accomplish most people do them all at the same time. In other words you visit the Policia Nacional to fill out the Interpol paperwork and turn it in, then go back in a couple of days to pick up the paperwork once they do the check and sign off on the paperwork.  Same with doctor, you visit doctor for exam, go to a lab to get your lab work samples taken and then return in a few days to pick up the doctors paperwork. I think you get the idea. to the bank to open the account,
As for getting paperwork legalized at a Paraguayan Embassy, I've seen people post here that they no longer have to do that as Paraguay finally accepts an apostle stamp from your home country.  This makes things much quicker.
Once you take care of the items you must be here for (medical check, signing paperwork, etc…) you can leave Paraguay.  Not sure if you can have someone pick up finalized paperwork for you once it's processed or if you must do it in person. I've seen people say both ways are what must happen. Most people, to include me and my family, picked everything up in person from Immigration once it was completed.
All these questions can be answered at Immigration in person once you get here. You'll just need to speak Spanish or have a translator available. And even if you use a lawyer or "helper" I'd be very sure to get the answers to alll your questions at Immigration before you pay money or leave your application in the sometime capable, and sometimes incompetent, hands of a lawyer or helper.  Good luck !