I’ve been trying to learn 2 or 0 and as far as I know have been following the steps. However, all three strings end up tOo close together and i end up landing on the wrong string or multiple strings. Any tips?
when i first started, i would practise spacing out the strings first with a dead yoyo. then i’ll try with it spinning
What I do is I make sure the first wrap around my non-throw hand index finger is near my knuckle. Then, the second wrap on my non-throw hand index finger is toward the tip of my finger. Well, I hoped this helped. 
Just really focus on where the string is going. If you have to break it down in steps first, then so be it. Make sure the first wrap is really close to the knuckle and the second wrap is closer to the tip of your finger. You should be able to land into it easy if you make the final wrap (the one that goes in trapeze) closer to the tip of your finger. In no time you’ll be able to do it second nature.
I had the same problem. try on the first swing around your fingers make it so the string is closer to you as close in on your fingers giving u more room to land the next throw more toward you tips of the fingers
make sure the string is on you middle finger. Do the first wrap near your knuckle, the second near the tip of your finger.
I use my thumb when i do Double or Nothing. My thumb keeps the middle string up and out of the way while the yoyo lands on the front string. I drop with my thumb as soon as it lands so it still looks smooth.
I’m moderately sure that Tyler Severance can pull it off fine with his index finger. But don’t quote me on it. 
What helps is to have a dead yo yo and just work on the form of the Double or Nothing.
The strings should be zig-zagged, kind of like a small Z, and spaced enough so that you can land the yo yo on the outer string.
The most IMPORTANT part, in my opinion, is the first two wraps of the Double or Nothing.
If you can get these two to be in good position, you’ll have great chances to land (or at least space out) the outer string.
This just takes a lot of grunt practice to set the strings in a position of your liking.
try to use multiple fingers. u have 10! ;D ;D ;D ;D