You need to configure your TV to your wireless network first. Look at your TV manual for specifics, but you need to enter the TV networking section and have it automatically obtain an IP from your gateway router and enter your security passkey. Once you actually have a good wireless connection, then start working on making the Netflix app work. Your TV may even want to download an update after connected, which is fine.
You should not need to connect your iPhone to the TV, and I assume that your iPhone works with your wireless Internet gateway?