Duplexes were never a popular building style here, so there aren't that many to choose from, although there are some.  

(LLC's were popular at one point but have been proven to be less attractive and "out of fashion" so to speak. 

The type of assets you buy will be related to how much money you have.If you are looking to place 50k etc. then it is more challenging.

I am barely starting and j am facing this simple challenge Jesse .

I landed myself a consultation job for the program director of a popular urban label!

Also, its never too early to start; build your credit up by being reliable and strategic in opening and purchasing things and challenge yourself to learn cocontinuously.

I have no experience at all on RE and I'm up for the challenge.

What are the biggest challenges / downsides to the industry?

I see some challenges in the local market (high first cost, high property taxes, older building stock, etc...) but also see a lot of positives (low vacancy rates, stable real estate prices).  

The challenge in investing education starts with the fly into town gurus who don't know your market and just want your money with minimal support.