A:AnswerNo certified HDMI cable is all you need. everything else is a bunch of hype. Make sure it is the latest HDMI version and shop for the best price.
A:AnswerYou only get 4k picture if you're watching some broadcast or on DVDs in 4k. Some programs are in 4k and some movies on Netflix. Go to netflix and search for 4k.
A:AnswerAll you should have to do is plug in the power adapter for the Firestick and connect to the internet. You don't need an HDMI cable. If you are connecting to a soundbar then you need an HDMI cable to go from the TVs eARC or ARC HDMI port to the soundbars ARC/eARC port.
If you already have an HDMI cable that has HS (High Speed) on the plug you are good to go. All high speed cables will carry 18 GBs. Unless your present cable is damaged, the new cable will make no difference.