Can I connect a laptop to tv with only a hdmi cable?
(for sound and picture) providing each one has the input
PS I am very tech challenged so if this is wrong can you tell me exactly what cables I can use (I know its based on what input/outputs the tv and computer have)
Answer:
Correct! As long as you have a HDMI cable and the right input/outputs, it will work!

Yes if the laptop has an HDMI port
Yes, it's the best way to do it in my book.