Which is better for rc tanks: Taranis x9 lite s or x9d? Keep in mind that I am brand new to this hobby and know nothing of transmitters except for "Taranis is good".

Don’t forget to check out the Taranis QX7. My first “hobby grade” radio and it runs OpenTx which makes assigning switches pretty easy. Plenty of switches and two potentiometers. Miles ahead of my Flysky i6s.

What is the empty box on the back of the transmitters? What is the best receiver? And do you guys know of any videos which can help a newbie like myself get started with hobby grade transmitters?

Search YouTube. Enter just what you asked for in the search box. You will be amazed.