First Time Home Buyer Using VA loan

[Minsub Song]

Hello, everyone I am a first time home buyer. About myself: 100% disabled (Permanent & Total) VA rating veteran. I am located in Denver, CO. Looking to buy our first home price range between $450-500K using the VA loan. We have already been pre-approved from Veteransunited.com for a rate of 3.375%. My family's goal is to buy a property to live for at least 1 year and have tenants.

Questions/concerns:

1. Any recommendation on refinancing VA loan for a lower interest rate? I am currently using Veterans United.

2. Any tips on using VA loan for a first time home? Any tips will be helpful