I have a few questions in how to start the offer/negotiation and listed the basic details of the property below.How would you structure a seller-financed deal?

You could also focus on the great financial advantages of renting/down-sizing (travel more, no more yard to care for/repairs, buy an RV, visit family more)Host a senior-focused event at your facility (maybe show an uncut version of Woodstock haha) or live music, a Social Security expert speaker or Doctor to address health issues, a fund-raiser, art show, etc. and hand out flyers with a special "one month free" coupon attached Have exercise classes for seniorsWeekly bingo nightsPromote your events for free on community calendars, newspapers, seniors sections of papersPrint door hangers and get some kids to hang the door hangers at trailer parks, older communitiesEncourage your current tenants to invite friendsRent a 15-passenger bus ($50) and offer free transportation to key eventsSponsor events at senior centers in the areaCo-Sponsor service club (Rotary, Kiwanis, etc who have many senior members) eventsPut up banners and balloons when you have eventsI hope at least a few of those ideas might spark some interest.

Based on the details above, we would love to understand people's point of views on if this is a good deal or not and/or something that we should undertake. 

@Russell Brazil My initial intention was to occupy the space and make it my permanent residence, however my fathers health deteriorated shortly after I made the purchase, which is why I made the decision to stay with my parents and try and rent the apartment out, rather then sell and take a loss.

Your question is just too broad to get a more detail answer IMHO. 

Shoot me an email with some more details.

If I waited until end of 2019, I could afford more.I will message you for the lender's details.

I might of got a little confused now that I read @Nicholas Horsburgh his reply he did not say PPM he said offering memorandum .. many would take that as a PPM  ( private placement memorandum) but maybe he meant like a detailed description in writing of what your trying to accomplish.Generally there are no real contracts for loans there are loan documents though Note  mortgage settlement statement and depending on the lender a whole host of other various and sundry documents usually disclosures so you can't sue the lender. :)

Good for you that your taking the plunge into this big, detailed world of real estate!

I'll spare you the details, but the houses generate enough rent in the first 12 months or less to cover the purchase price.