There could be a few reasons why your Vizio TV does not have physical volume buttons:
1. Smart TV Functionality: Many newer Vizio TVs come with smart features and are designed to be controlled via a remote control or through a smartphone app. In such cases, the volume controls are often accessible through the remote control or the app, rather than having physical buttons on the TV itself.
2. Slim Design: Vizio, like other TV manufacturers, may opt for a slim and sleek design that minimizes the number of physical buttons on the TV. In order to achieve a more modern and minimalist appearance, they may eliminate certain physical buttons, including volume controls.
3. Cost Reduction: Removing physical buttons can help reduce manufacturing costs. Manufacturers often try to simplify the design and eliminate unnecessary components to make the product more affordable.
If your Vizio TV does not have volume buttons on the TV itself, you can control the volume using the remote control, through a smartphone app, or by connecting external speakers or sound systems that have their own volume controls.

The input for your VIZIO TV will depend on the device you are trying to connect. Here are a few common input options:
1. HDMI: If you are connecting a Blu-ray player, gaming console, or streaming device, use the HDMI input.
. Component: Use the component input if you have a device that uses red, blue, and green cables for video, and red and white cables for audio.
3. Composite: This input uses the yellow, red, and white cables and is typically used for older devices like VCRs or DVD players.
4. VGA: If you are connecting a computer or laptop to your TV, use the VGA input.
5. Antenna/Cable: If you are connecting an antenna or cable directly to your TV, use this input.
Please consult your TV's user manual or check for labels near the TV's ports to determine the appropriate input for your specific device.

The Vizio M70-C3 is a model from 2015.

To set up your Vizio TV for the first time, follow these steps:
1. Unbox the TV: Carefully remove the TV from its packaging and place it on a flat surface.
2. Connect the power cord: Plug one end of the power cord into the back of the TV and the other end into a power outlet.
3. Turn on the TV: Press the power button on the TV or use the remote control that came with your Vizio TV.
4. Select the language: Use the remote control to navigate through the initial setup menu. By default, the language selection screen should appear. Choose your preferred language using the arrow keys on the remote control and press OK or Enter.
5. Connect to a network: You can set up a wired or wireless connection, depending on your TV model and available network options. If you have an Ethernet cable, connect it to the LAN port on the TV for a wired connection. For a wireless connection, navigate to the "Network" or "Wi-Fi" section in the setup menu, select your network, and enter the password if prompted.
6. Set up parental controls (optional): If you want to enable parental control features, navigate to the appropriate section in the setup menu. Follow the on-screen instructions to create a PIN or password and configure the desired restrictions.
7. Scan for channels (optional): If you use an antenna for over-the-air broadcast channels, select the "Antenna" or "TV" option in the setup menu, and then follow the on-screen instructions to scan for channels. This step can be skipped if you plan to use cable or satellite.
8. Complete the setup: Review and confirm your settings, including time zone, daylight saving time, and location, if prompted. Once everything is configured to your liking, select "Finish" or a similar option to complete the setup process.
Your Vizio TV should now be set up and ready to use. Enjoy your new television!