Do I need…?
I’ve just started using Ableton with no hardware.
Do I need a keyboard looking midi controller too if I buy Ableton Push?
Nope.
Need is a very subjective word.
You can get all your notes input into Live with Push, and some prefer it to an actual keyboard. If you’re used to playing keys, it’s pretty awkward doing so from Push. So, if you play, it might be something to consider - give Push a try and see how it feels to you, otherwise as Patch said…nope.
You can use your computers keyboard to play notes
you don’t even need ableton… just ask the pros 
Although for writing a keyboard does help, but so does a guitar 
Please elaborate on this…
ghost producer joke lol
Well can do what lots of people I’ve noticing do is just buy sound packs and sample disks and sequence throw some effects and tweak the odd loop and now you have another beatport number #1 for the low low price of degrading a already polluted market… Yes it happens don’t believe me pick up any sound pack make a 1mjnute clip put on soundcloud and watch how many tracks it tells you is copyright infringement
So how do you distinguish “real” tracks from “fake” ones?
You will have to post examples.
Examples won’t help you. There’s no difference to anyone between quality of tracks except for a small community of artists will know you half ass your music and never take you seriously as a producer.
That means buying a sample pack with construction kits and copy pasting them to make a song and calling it yours. All while the packs are royally free and you can technically do that, people will know you took something commercially available to everyone and tried to pass it off as if you were the creative brains behind it.
I use ableton without any sort of controller. I do know that if I were to do anything more extensive than making a few remixes I would want a controller.
I see sound packs as a great way to learn. Idk if I could ever a call a track “mine” if it was constructed using a sample pack.
I write everything on my guitar, record some chords, and rarely use my midi keyboard these days… lol really the software does it all.