Some questions from a beginner

Hello friends!
I’ve just configured my flightfeeder
My flightfeeders version is 7.3.1
Here are some questions…
1.what can I see if I plug the hdmi port onto the tv?
2.what the port that next to the hdmi do?is that a 3.5mm audio line?
3.all of the status are green except "mlat "…how do I configure it to let it work?
4.im gonna download the "open street map"to use my flightfeeder offline near airport when I go take picture.(just go to the airport and find what plane will arrive or take off by flightfeeder)so can I download the map that I can see the map without internet …how to do it ?

The HDMI output shows another version of the status screen that’s shown on the touchscreen.

2.what the port that next to the hdmi do?is that a 3.5mm audio line?

It is a 3.5mm audio jack, it is not used.

3.all of the status are green except "mlat "…how do I configure it to let it work?

Looks like you have set your site location, so there is nothing more to do here. mlat needs a number of nearby sites and suitable ADS-B traffic to work, which is kinda out of your control.

4.im gonna download the "open street map"to use my flightfeeder offline near airport when I go take picture.(just go to the airport and find what plane will arrive or take off by flightfeeder)so can I download the map that I can see the map without internet …how to do it ?

This isn’t possible unfortunately, the FlightFeeder is designed to work at a fixed location with a continuous internet connection.

So, what the usb port do ?

i use the USB port on my Flight Feeder to power my 4G Wireless Router am sharing data using 4G USB dongle ,

https://c7.staticflickr.com/6/5830/30367653206_69b5a6d383_z.jpg20161016_202213 by Ali Talla, on Flickr

It is a USB port. You can connect a mouse to interact with the HDMI display (not much point when you have the touchscreen), or you can connect some brands of wifi dongle if you need wifi connectivity and the built-in wifi is not good enough (it does not have much range).