Anyway I just wanted to know the basics of the game. I've so fat I've worked out that you're pretty fucked if you're in the air and the opponents on the ground but beyond that I'm pretty clueless. If you're opponents reaching the +100%s is there a consistent universal way to knock them out or is it always character dependant?
It's largely dependent on the character you're playing and what moves can KO. Each character has certain moves that can KO and others don't have reliable KO options, you need to figure those moves out on your own (or you can ask people here, like myself, I'm sure we can help you in that regard). I suggest reading up on smash mechanics on
www.ssbwiki.com and navigating through there to find out how the game works at a deeper level. You can also always go to
www.smashboards.com and try to sift through the subforums to find threads that go into even more detail on match-ups and stuff but I'd recommend starting at ssbwiki for the mechanics and sometimes the wiki even links directly to Smashboards threads anyway. The wiki is easier to navigate, as well.
For videos, I have three suggestions for you to watch:
Wak's Advanced How to Play (it's got a lot of Melee exclusive stuff but there's quite a bit covered in there that is still very relevant to Smash 4 -- you just need to know what's exclusive to Melee and separate that out from what's still possible in Smash 4).
CosmoWright's Melee Introduction video (Although this doesn't follow a specific set order of things there's a lot of good things he talks about in this video that I absolutely recommend you watching, again there's some Melee exclusive stuff but much of the broader terms and explanations do still apply to Smash 4).
Fundamentals of Melee (Again, another Melee-specific video but this one actually details the basics that apply, generally, to all Smash games. If there's anywhere you should start first among these three videos, it's probably this one, then Cosmo's, and then Wak's. But feel free to check them out in any order).
Someone should save this post for the future when more people ask in the future because I'm not going to type it all again lol.
Oh, you can also check out UltraChen's First Attack which covered Super Smash Bros. Melee and goes over some of the basics as well
here if you'd prefer that (it's pretty long though BUT it does provide great insight and explains a lot, especially in high level play).
I hope this post helps (and that you see it because the last person who asked about this didn't even respond back to me telling me they're going to check the stuff out D: )