If you do not feel comfortable pursuing additional growth, I'd wait it out just a bit. 

The key is understanding your comfort level with managing multiple units right out of the gate.. 

This upgrade not only improved comfort but also significantly modernized the property.

A window A/C might keep it comfortable, but it often doesn’t meet the standard for counting it as fully finished square footage.

You may want to look at concessions to help cover costs or buy down your rate to a comfortable payment. 

And try to master those taking as much time as you need to be comfortable with it.

A primary residence will most often provide more favorable loan terms so if you are willing to wait one year while you living in your new property and are comfortable with renting out your primary residence to a tenant, then getting something such as an FHA loan is a good strategy to minimize your upfront costs and hopefully get better loan terms.

I am most comfortable with long-term rentals, but I would like to try a flip or two to build my capital.

Face the fear--get yourself in front of more sellers.Little by little, your presentations will become more comfortable, and your success rate will increase.  

If you’re working with VA-savvy lenders who are comfortable with your plan and don’t impose stricter rules, you might be able to rinse and repeat as you described.