My oldest child is attending online college from Portland and renting a room.

I'd also recommend prioritizing municipalities that don't have short-term rental limitations as you'll see greater returns with STRs, especially in the midterm as you wait to refi.

The high PM costs can absolutely be justified. 

I am using a new tax professional on the recommendation of another investor, who has since passed away- he recommended his daughter.

Secondly, make sure your units are available on traditional rental sites such as Furnished Finder, Airbnb, Zillow, etc. - These are the two channels where these companies will seek out listings for their housing requests.Longer term you should be networking with businesses in the area that are known for having housing needs for their employees.

I am turning 18 in less than 3 weeks and can say I have been a business owner throughout my high school journey, from small local hustles to building products in my basement to sell online.I am an aspiring Real Estate investor reading many books and conducting hours of research hoping to build an impressive real estate portfolio in the future!

I've been looking at Furnished Finder and Travel Nurse Housing online but would love to hear from anyone with this experience.

I would like recommendations as where i should go to invest it.

Since you want to invest in another state, I highly recommend you read "Long-Distance Real Estate Investing" by David Greene.1.

There is a list of recommended STR lenders on BP.