@Stanley92 I'm not sure what you mean by what you need to do to initially furnish the house.
First you have to decide how many people the house lends itself to hosting. As it's a 2 bedroom, I'm thinking 4 guests? You say there's a loft, which I guess could sleep a couple more, but there's just the one bathroom, so maybe better to limit to 4. Maybe the loft could be set up as a hang-out space, with a mattress and lots of pillows, maybe as an entertainment area- TV or DVD player and monitor and a bunch of movies. So you furnish it the way you would furnish your own home- beds, bedside tables, lamps, a place to put clothes, a desk, a chair. Dining table and chairs to accomodate number of guests. Basic kitchen gear and appliances. Some outside chairs and small tables for the deck or maybe a picnic table if there's space.
Keep furnishings simple. Things which are easy to clean. Guests often don't take very good care of things, so don't go high-end for the kind of place you describe. You can sometimes find good stuff on Craigslist. Don't use knicknacks- just more to dust and clean and get broken. Buy dishware that you can replace easily and buy matching pieces individually, not sets that can't be matched when guests break one. Think Ikea plates, or restaurant style plates.
There are no agents who come around and advise you. Use the available filters that would closely match your place on the Airbnb website as if you were searching as a guest- 4 guests, entire house, etc. in Portland and surrounding area. Look at the photos, read the listing descriptions. This will give you an overview of what is being offered and those will be your competition.