Commercial deal??

[CTNoob]

Hi All
I posted this similar message in the Beginners section as I am a very NEWBIE.  At any rate, I've stumbled across what appears to be a good commercial deal.  The seller appears to be motivated and I can make the numbers work (from the liabilities that I am aware of).  However, I've only purchased a residential property and have NO experience with commercial properties.  The property is in excellent condition (a little paint is all it needs now)  This property is less than a quarter acre with two apartments that are currently rented with tenants that have been there 4+ years.  One of the tenants is a section 8 tenant.  The other part of the building is a small vacant space that was previously used as a fried chicken restaurant.  I can make the numbers work with the small commercial space being vacant and then explore lease options after I secure the property.  My questions are:
1.  Besides the 25% down (which I can acquire);  what are the other pitfalls of commercial investing.  Can I obtain a loan fairly easily as I have done residentially? (I am starting to check this out today)?  
2.  I have not dealt with section 8 at all.  Can you raise rent on a section 8 tenant?  What are any pitfalls/positives with section 8.
Any advice would be greatly appreciated.
Regards,
Art