Rental Property Completed, I feel like it's not enough

[Thoai Han]

Hello BP! My first rental unit is finally complete and I have two tenants in place. I own the property free and clear, but I am stuck on what decisions to do next. 

So I've came to these options.
- Should I purchase another property (D to C grade property), renovate it and bring both of these properties to the bank to shop for a good HELOC rate? (Which takes about 4 to 8 months depending on how life goes) Or...
-Should I wait to qualify for a mortgage and purchase a B to A grade property in a desirable area?
-Wait to qualify for a loan to purchase a commercial property 6 Units + Storefront 

I'm the first of my generation here, there's no one to ask for advice except the BP family. Any advice guys?