@Minsub Song
I am a veteran as well and have used a VA loan twice. Both times were purchases of a primary residence. The first was zero down and we lived there for two years (Oregon) and then moved to Colorado. We rented that property, but it was always break even on cash flow after maintenance and property management. Refinancing never made sense after it became an investment property, since we could not beat the rate, which would have been the only way to make to cash flow more. Luckily it has appreciated well. The second purchase we used what was left of the entitlement but needed to make up the difference on what entitlement could cover, so we had about 6.5% down. We were not required to get PMI with this low of a down payment.
If you aim on buying with the VA loan and then renting the property in a year here are a couple of things to consider:
-Refinancing to move to a conventional mortgage would be unlikely to yield a lower interest rate. If your idea would be to then do more VA loans after the refinance frees up your eligibility, then that could work. I have heard reclaiming your VA entitlement is a bit difficult and can only be done once.
-If you plan on buying many more houses, try putting up a down payment so you only use a third or a quarter of your eligibility. This is for two reasons:
---zero down properties are very unlikely to cash flow unless you do house hacking, vacation rentals, or another creative strategy.
---if you bring a down payment and have entitlement remaining you can use the VA loan multiple times without needing to refinance other properties to reclaim it. The biggest advantage here is being able to put down less that 20% and not have to worry about PMI.
-Like @Dan Mackin said, VA loans can be undesirable to sellers. My first VA loan was a very long and difficult process and it certainly did not make the sellers happy. Best recommendation there is to find a proactive lender who get stuff done quickly and does full underwriting on you as a borrower before you go out to make offers. Being pre-approved is much better than being pre-qualified. USAA was the bank for my first loan and I had a higher interest rate, longer process, higher closing costs, and much more difficulty getting in contact with the loan officer than with my second purchase. PM me if you would like the contact for my second lender.
Good luck!