I've been trying during these days and I still haven't finished one practice yet. Can someone please tell me if my Koopas are in the right positions?

In the case the Koopas are in the right spots, how do I trigger the wrong warp? Sometimes I don't press anything and when Mario reaches the bottom screen he just stands there. Other times I jump and well it kind of triggers the glitch but immediately crashes the game. Is there any specific inputs that I need to do to trigger the whole thing?

This is my most recent practice from like 40 minutes before this post if you can help me I really appreciate that:

Thanks in advance.

Thank you, I will keep practicing!

I did it! Thank you very much, now it's finally time to get some runs and hopefully a PB soon!